For the first time in 10 years, the NFPA recently compiled all of the National Electrical Code’s rules on residential wiring in one publication in response to requests for a one-stop home wiring code.

First on the electrical wire color code is black. “Black wires are most used as ‘hot’ wires in residential systems,” says master electrician Allyson Saling with Frontdoor home services app. “Hot or ...