This is the most common, and the easiest wiring diagram to follow of any of the wiring diagrams for a 3-way switch circuit. This wire diagram shows the wiring for source power into the first three way switch, then 3-wire cable to the next 3 way light switch, and then on to the light or light fixtures.
The 3-way circuit is a very common system found within most residential installations.
3-ways are used any time that you want two switches to operate one light (or lights).
The best example of this would be at either end of a long hallway, or at the top and bottom of a stairwell.
Watch a Video Explaining 3-Way Switches
Confused by the 3-way switch? Terry Peterman, the ‘Internet Electrician’ provides a visual explanation of 3-way switches in this short, informative video. Click here to view.