Here the exhaust fan is controlled by a timer instead of a switch. There should be two hot wires and a ground coming out of the timer casing, splice one of these to the hot source. Spice the second to the black, cable wire running to the fan. Splice the source neutral to the white cable wire and the ground to the ground wires. At the fan splice the wires, matching the colors of each.
This diagram illustrates a switch and receptacle in the same outlet box located in the middle of the circuit. This wiring allows the electricity to continue from the receptacle, on to any other outlets in the circuit and it provides a switch to control a light fixture or other load, such as another receptacle or a fan.
To wire an exhaust fan to a wall switch, use this diagram. These fans usually come with a small electrical connection box welded to the side of the housing. There will be a cover on the connection box that fastens with a small screw. Open it, pop the plug out of one of the wire holes and thread a wire clamp into it.
The source hot is spliced to the red wire which is connected to the bottom terminals on the switch at the other end. The black wire is connected to the top terminal on the switch which runs power back to the fan where it is spliced to both the black and blue fan wires.