Switch-Switch-Light

This is probably the simplest of the three-way switch configurations. The source of power comes into the first switch, is routed through it to the second switch, for the dual control, and then comes to the light. As in all of the configurations, the neutral goes straight from the light to ground, although it must travel through several splices.

This diagram presumes that metal boxes are being used, as can be seen by the ground connections to the boxes. If plastic boxes are used, these connections to the box will not be necessary. However, ground wires should still be spliced at the appropriate points.

Three-way switch wire (commonly refered to as "three-wire cable with ground") is usually purchased from a spool, by the foot, in a hardware store. This being the case, you should be careful to measure the amount needed before purchase. It is always best to get a couple feet extra, just to be sure because you can always shorten the wires. Splicing another wire to it to make it longer should generally not be done as it would require another accessible electrical box.