To wire a 3-way switch circuit that controls both the fan and the light, use this diagram. As with all 3-way circuits, the common on one switch is connected to the hot source wire from the circuit. The common on the second 3-way switch is connected to the hot wires on the fan/light.
The black wire is splice to the output on the speed controller and to the black, fan wire at the other end. The red wire is spliced to the output on the dimmer and to the blue, light wire at the other end. The neutral from the source is spliced in the switch box with the white wire, and to the neutral wire on the ceiling fixture at the other end.
In this arrangement a light fixture and exhaust fan are wired to the same source. The light is controlled with a single-pole switch and the fan controlled with a timer as in the previous drawing. The hot source is spliced to each controlling device and the output of the controllers are connected as in the previous diagrams on this page.
This ground fault circuit interrupter wiring diagram of the same device leaves the switch out of the protected circuit. With this arrangement the receptacle is protected but the switch remains outside the circuit. This arrangement can be used to control a light or other device where the extra protection of a gfci is not necessary.