What a big topic!  Hopefully this gives some good information you can use.

The type of wiring in residential homes generally depends on when and where it was built.  Has it been updated? In the older homes, knob and tube type wiring was the norm, replaced later by plastic-sheathed wiring.

In most cases the newer plastic-sheathed wiring is copper, insulated with plastic and then wrapped with insulation and another layer of plastic for protection. Breaker boxes are another story; sometimes a well-meaning home owner can inadvertently make things unsafe. [Read more…]