Asbestos is a carcinogen, meaning it increases the risk of cancer. Inhaling asbestos fibers is linked to several respiratory issues, including asbestosis, or scarring on the lungs, lung cancer, and mesothelioma, another type of cancer. There's also a link between asbestos exposure and an increased risk of colon cancer and other cancers of the digestive system.

Usually, the people most at risk for disease related to asbestos exposure are those who spend a lot of time working around the material without protection. Electricians who work with asbestos wire have a higher risk of developing mesothelioma or lung cancer due to their exposure.

Many homeowners may never have to test their homes for asbestos. Asbestos particles are only dangerous if they become airborne. If you plan to do construction or notice damage to piping, siding, or drywall, you should hire a specialist to test for asbestos. 

If you plan to remodel your home or have any concerns, you should have your home tested for asbestos just to be safe.

Knob and tube wiring is an older type of electrical wiring that's no longer used and generally not considered safe. However, some homes still have it, or may have a knob and tube wiring system that was incorrectly modified or rigged to work with a modern electrical system. Knob and tube wiring may contain asbestos insulation, but the only way to know is to have the material professionally tested.

Unfortunately, asbestos is not easily identified and can often be hidden in plain sight in your home. While it can look like fluffy fibers, tiny pieces can also appear in materials like plastic or cement, making it impossible to identify on your own properly.

Plus, since asbestos is so dangerous when disturbed, you should never root around to try and find it. This job is best for a professional who can test for the material properly.