How to Install a GFCI Circuit With an Outlet & Switch Wired for a Garbage Disposal

Locate the wall stud where you want to install the outlet and switch, using a stud finder.

Hold an old-work 2-gang electrical box against the wall next to the stud, and trace the outline of the box onto the wall. The old-work box is designed for use in finished walls, and "2-gang" indicates that the box can hold two outlets, two light switches, or one of each.

Cut a hole in the wall with a drywall saw for the electrical box.

Run an electrical cable between the garbage disposal and the hole in the wall, and another cable between the hole in the wall and your home's main electrical panel.

Punch out the knockout holes in the back of the 2-gang electrical box, and slide the cables through the holes into the box. Slide the box into the hole in the wall and screw it to the stud.

Cut away about 2 inches of sheathing from the electrical cables, and about 3/4 inch of insulation from the white, black and green wires inside the cable with wire strippers.

Bend the ends of the wires into a hook shape with needle-nose pliers.

Hook the black wire in the cable that leads from the main electrical panel around the brass screw marked "Line" on the back of the GFCI outlet, and tighten the screw. Hook the white wire in the cable that leads from the main electrical panel around the silver screw marked "Line" on the back of the GFCI outlet, and tighten the screw. Installing the GFCI outlet first protects anything installed on the circuit after it.

Cut a short piece of cable to fit between the GFCI outlet and the light switch. Attach one end of the black wire to the brass screw marked "Load" on the GFCI outlet, and the other end to the brass screw on the side of the light switch closest to the outlet. Attach one end of the white wire to the silver screw marked "Load" on the GFCI outlet, and the other end to the silver screw on the side of the light switch closest to the outlet.

Attach the black wire from the cable that leads to the garbage disposal to the other brass screw on the light switch, and connect the white wire to the silver screw.

Cut a piece of green (ground) wire 3 to 4 inches long. Attach one end of that wire to the grounding screw on the GFCI outlet.

Connect the other end of the green wire connected to the GFCI outlet to the green wires in the electrical cables leading to the garbage disposal and electrical panel with a plastic connector cap. This is called pigtailing.

Wrap electrical tape around the terminal screws on the sides of both the GFCI outlet and the light switch.

Tuck the wiring into the electrical box and screw the outlet and switch into the box with the terminal screws.

Screw the plate cover over the outlet.

Connect the wiring to the garbage disposal.

Hire an electrician to connect the circuit to your home's main electrical panel.