Two or three wires will be attached to the switch: an incoming hot wire, which is black; a return wire, which carries the load to the fixture and may be black, red, or any other color except green; and sometimes a grounding wire, which is green or bare copper.

What are the 3 terminals on a light switch?

There are three screw terminals on the body of the switch, in addition to the green grounding screw. One screw, known as the common, is a darker color than the others. The other two screws, usually a lighter brass color, are known as the traveler terminals.

What happens if I wire light switch wrong?

But heres the catch: If you connect the circuit wires to the wrong terminals on an outlet, the outlet will still work but the polarity will be backward. When this happens, a lamp, for example, will have its bulb socket sleeve energized rather than the little tab inside the socket.

How many wires can be on a light switch?

Three wires Three wires will be attached to your switch: a hot (black) wire, a neutral (white) wire and a ground (copper) wire. The black and white wires are attached using brass screws.