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.

Asbestos was commonly used in cloth wiring, but not all types of cloth wiring contain it. The age, condition, and appearance of the wiring can provide clues as to whether asbestos is present or not, but the only way to know for sure if the wiring has asbestos is to have it tested.

No, but it’s common that they do. Gravity furnaces weren’t terribly efficient so wrapping either the ductwork in asbestos, the furnace itself, or both, was something done regularly. This allowed the system to retain more heat. At the time, this greatly enhanced the efficiency of the furnaces but it wasn’t until later that we became aware of just how carcinogenic and dangerous asbestos could be.

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.