Just because you can't see any trouble in your home, it doesn't mean danger is not there, lurking in your attic, floor tile or fuse box.

Indeed, your innocent little bungalow has many ways to sicken or kill you, from odorless deadly gas to electrocution to fire. It may sound silly, but something as trivial as dryer lint can take your whole house down - and you with it. (Bing: How do clothes dryers cause fires?)

But you can head off most of these home disasters with a few simple steps.

Here are the six tests or checks that homeowners should perform to keep their houses safe:

1. Radon test
Radon, a radioactive gas, is one of the deadliest home problems, causing about 21,000 lung-cancer deaths each year, according to the Environmental Protection Agency.

This odorless, colorless gas, formed from the decay of uranium found in virtually all soils, rises through the ground and sneaks into your home through cracks and other holes in your foundation. Once inside, it can get trapped and build up, especially during winter months when windows are closed.

Nearly one in every 15 homes is estimated to have elevated radon levels, the EPA says. But many people don't test for it because they think it's a problem only for homes with basements.

"You can be susceptible anywhere," says Jack McGraw, a Hickory Hills, Ill., home inspector and former firefighter. "It can come through the slab (foundation) of a home. It can come through the crawl space."

Indeed, he says, with the advent of bigger kitchen exhaust fans exerting more negative pressure on a home, some people are actually sucking it into their house from below.

And there's no reason not to test for it, with reliable test kits costing as little as $20. There are two types of home kits: a long-term kit that is exposed for 90 days before you ship it to a lab for analysis and a short-term kit exposed for two to seven days before you send it in.

The long-term kits, including this one that Consumer Reports called a "best buy" for $28, are the most reliable and accurate, it said in a 2008 review. However, Consumer Reports also got "very good" results with at least one short-term test it reviewed.

So what constitutes cause for alarm? Radon is measured in picocuries per liter of air - or pCi/L -with the average indoor radon level estimated at about 1.3 pCi/L.

If your home tests at 4 pCi/L or higher, the EPA recommends installing a radon reduction system that will vent the gas outside. However, it says, slightly lower levels also pose "some risk" for cancer.

To find a qualified contractor, check with your state radon office. And remember to test your home again after you do the work to make sure the problem is fixed.

2. Carbon-monoxide monitoring
While you're safeguarding against unseen risk, don't forget that other deadly gas: carbon monoxide. When you're at the hardware store picking up a radon test kit, also purchase a carbon-monoxide detector. The Centers for Disease Control and Prevention recommends that every home have one to avoid the 500 needless deaths each year caused by gas leaks from appliances and furnaces.

Carbon monoxide gets trapped in a house when a furnace vent or chimney flue gets blocked, says air-conditioning contractor Bobby Ring of Meyer & Depew Co. in Kenilworth, N.J. Most newer, high-efficiency models shut off when a blockage happens, but that's not the case with older models.

A battery-operated carbon-monoxide detector mounted on each level of your home, preferably near bedrooms, can provide peace of mind for as little as $40.

But, Ring says, it's also important to get your heating system checked once a year before the cold weather hits to spot problems that could generate carbon monoxide, such as improper venting, cracks or holes.

"You're lighting a small fire every time the furnace comes on," Ring says. "You want to make sure that burner is operating safely."

Homeowners should also take these other precautions to cut their carbon-monoxide risk, according to the CDC:

  • Don't warm up your car in the garage. Take it outside.
  • Don't use a gas stove to heat your house in the winter if your power goes out.
  • Don't run a portable generator inside your house. Get a long extension cord and put it as far away from your front door as possible.

3. Lint check

Most of us may be diligent about cleaning the lint trap inside the dryer with every load of clothes. But how many of us clean the exhaust duct and dryer vent regularly? Not many, home inspectors say, and that's a huge problem.

"They are an accident waiting to happen," McGraw says.

Clothes dryer fires account for about 15,600 structure fires, 15 deaths and 400 injuries annually, according to the U.S. Fire Administration's National Fire Data Center (PDF file). And the cause of most of these accidents is "failure to clean," according to the center.

To keep highly combustible lint from sparking a fire, homeowners should check their vents and ducts behind the dryer periodically. (Vents should lead outside the house.) Moreover, make sure the area behind the dryer is free of lint, old socks, etc.

And make sure you have the right kind of duct behind your dryer. Manufacturers now advise homeowners and builders not to use plastic flexible dryer ducts between the vent and the clothes dryer because they can provide fuel for a fire. Likewise, replace accordion-style aluminum tubes, which can easily trap lint and get crushed. Instead, use more rigid metal ducts.

4. Assess your electrical risk
In some cases, checking for problems requires educating yourself first. David Shapiro, an electrician in Washington, D.C., recommends that homeowners get more familiar with their wiring, so they can pinpoint trouble spots.

"The most important tests here involve using your eyes," he says, not those of a professional electrician.

Every homeowner, he says, should know where his or her electrical panel is and what each item in the panel controls. Which one turns off the appliances in the kitchen? Which one controls the bedroom lights?

"You need to know what fuse to unscrew or which breaker to flip" when something goes wrong, says Shapiro, author of "Your Old Wiring."   

Once you know what you're looking at - and which breakers connect to which outlets - you can see if your wiring is putting your house at greater fire risk.

One dangerous wiring problem he sees frequently is homeowners using circuit breakers greater than the mandated 15 or 20 amps to control lights and receptacles for common household appliances. (You can find this capacity marked on the handle of the breaker or the body of the fuse, Shapiro says.)

It's not only illegal. It's a serious fire hazard, he says, because the breaker won't trip when there's a problem and shut off power to the sparking outlet.

"Somebody should get there lickety-split" to fix it, Shapiro says.

Also, he says, make sure you have your panel labeled for specific outlets - not just "bedroom lights" - so you can kill power quickly if something goes wrong. 

5. Mold inspection
Moisture is not your home's friend. And it's not yours, either. When mold spores spread, they can cause asthmalike symptoms and other respiratory conditions. Some strains can prove deadly.

The main problem isn't moisture outside the house but moisture inside that can't get out, McGraw says. In some cases, it's a bathroom venting to the attic rather than outside, or an amateur insulation or roofing job that has covered up vents in a house.

"If you put a plastic bag around (your house), it's not going to be able to breathe," he says. Not even in hot, arid climates like Phoenix.

Other mold cases can be prevented by periodic checks of the traps underneath your sinks.

Leaking traps, pushed or crowded by hair dryers and boxes of cosmetics, can spur the growth of mold in the cabinet and wall behind it - and sometimes in the ceiling below.

Every homeowner should check the traps once a year, and make sure the house is vented properly to start with, he says.

If you know you have mold and want to see how widespread it is, experts suggest consulting a professional, as many of the home tests Consumer Reports surveyed were not reliable. 

To find a licensed mold-remediation contractor, you can contact your local environmental protection or public-health department or contact professional organizations such as the American Industrial Hygiene Association, the American Conference of Governmental Industrial Hygienists or the Restoration Industry Association.

However, if the offending mold covers an area smaller than 10 feet, the EPA says it's probably OK to try removing it yourself by scrubbing the moldy area with detergent and water, then drying.

6. Tests for the toxic twins: lead and asbestos
Before you launch into any home project - whether it's a small painting job, new flooring or a kitchen remodel - you need to know what you're ripping into. If your home was built or remodeled before 1978, you should test for lead paint or asbestos-laden building materials before you begin any work.

Why? Lead paint or asbestos-filled vinyl flooring usually aren't problems when they're left alone. But they can be a big problem when they're sanded, scraped, drilled or broken apart, experts say. Then, lead-filled dust can be inhaled or ingested, causing damage to the nervous system. When disturbed, asbestos flooring or insulation will release fibers that can be inhaled and remain in your lungs a long time, increasing your risk for lung cancer.

Lead test kits sold in hardware stores are inexpensive - you can test several areas for less than $100 - and deliver mostly accurate results if the old paint is exposed properly, experts say.

These kits use one of two chemicals to detect lead, changing color if there's a problem. Lab tests for lead may be more sensitive, Consumer Reports says. Ship-away lab tests also are available for asbestos.

If you find lead or asbestos in your home, don't remove it yourself. Instead, find a contractor certified in working with these materials to minimize risk.