If you have an older electrical system with fraying wires and other signs of damage, removal  may be the best course of action. When asbestos begins to break down, it's more likely to become airborne, increasing the risk of health issues when it's inhaled.

However, if the system is in good condition and doesn't have visible signs of wear or damage, leaving it alone may be the safest course of action. An asbestos abatement and removal professional can help you determine the best way to proceed.

Asbestos testing takes place in two stages—collection and lab testing. Collection can take less than 20 minutes if a professional manages to get a direct sample. If air samples are required, then the pro will set up a testing device and return to collect it. In both cases, the sample is sent to a lab and results are confirmed or denied usually within one to two days.

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.

According to the National Cancer Institute, asbestos-related diseases can take anywhere from 10 to 40 years for symptoms to appear. The health risks increase with prolonged and heavier exposure. Risk factors also include:

• Amount of exposure

• Chemical makeup, size, and shape of the asbestos fibers

• Length of time a person is exposed to asbestos

• Genetic factors 

• Source of exposure (direct exposure or secondhand exposure from someone directly exposed)