Recently I wrote about wiring wall outlets. This time I want to talk about wiring wall switches and light fixtures. If you've ever looked at an installed wall switch, you might see that there are two black wires attached to it, and no white. Or you might see a black and a white. Or there might be a black and a white with a black mark on it. Does it make a difference? And if so, what is the difference? Let's find out.
Check out Plumbing & Mechanical's September 2017 issue, featuring our cover story on PHCC CONNECT 2017. Other features include the benefits of heat pump water heaters, preventing cockroach infestations with drain maintenance, and much more.