Wiring Diagram 2 Humbuckers 1 Volume 3 Way Switch – The visible difference between a common switch plus a three way switch is a more terminal,or link. A 3 way switch has 2 terminals that are possibly metallic or brass shaded and another terminal which is darkish colored. The metallic or brass terminals are known as vacationers or messengers and also the dim colored terminal is known as the most popular. If all 3 terminals seem comparable in colour, the common terminal will be identified by the term “popular” stamped on the back of the switch.