Famous Replacing Light Switch 2 Black Wires Ideas. Skipping this part or doing it incorrectly could be fatal. Hook 1 traveler wire that is red or black onto each of the brass terminal screws.

Black wires that go to black or brass screws, copper or green ground wires attached to green or copper screws and neutral white wires. ;) but srsly, my current home is partly an old 2 wire. Skipping this part or doing it incorrectly could be fatal.