Switch-Light-Switch

The switch-light-switch configuration comes about when the source of power comes to the light through one of the switches. The diagram at left shows how this would work if this configuration were at the end of a circuit.

Again, we must make use of the three-way switch wire that contains three wires and a ground, the extra wire is red and does carry a charge. In this case it runs between the two switches. As usual, the light must be connected to a black wire only at the end of the second switch. This ensures that the electricity must go through both switches before it reaches the light.

Note that the only real neutral connection here comes directly from the light. It is well to note that three-way switches can be used for items other than lights, such as ceiling fans and even outlets.