Adding An Outdoor Outlet For Your Holiday Light Displays

22 July 2015
 Categories: , Blog

Why wait until the cold of winter to install an exterior electrical outlet for your light displays? There is no reason to continue to run extension cords from inside your home.  

Installing a new outlet is relatively simple if you have an indoor outlet close to the intended outdoor location, and can be done with a minimal amount of tools and supplies. 

What you will need:

GFCI (Ground Fault Circuit Interrupter) outlet 

These outlets are used in damp locations and will shut down if the danger of electric shock is present.

Two metal gang boxes

These are electrical boxes in which outlets are housed.


This is a thin, metal pipe through which electric wire is run. You will need half-inch-diameter conduit for this project, length needed will vary according to the distance from the indoor outlet to the outdoor location.

Ninety-degree elbows and connectors for half-inch conduit.

One five pack of half-inch ninety-degree elbows and one five pack of connectors to hook conduit to gang boxes should be sufficient.


This is needed to cut conduit to the required lengths.

Drill with three-quarter-inch masonry bit for drilling through wall


Check the circuit breaker that controls the indoor outlet from which you intend to run your new outlet. If "15" is printed on the breaker, use at least fourteen gauge wire, if "20" is printed, use at least twelve gauge wire.

Measure the distance from the indoor breaker to the new location and add several feet to the result to determine the length that you will need.

Wire cutter/stripper

This is needed to cut wire and strip insulation from the ends.

Beginning the installation: inside the home

Begin by shutting off the circuit breaker that controls the indoor outlet. Remove the screw that holds the cover plate, then the two screws that hold the outlet inside the outlet box.

Remove the outlet and disconnect the wires on the side of the outlet, then remove the outlet box from the wall. Next, move the exposed wires out of the way and drill a three-quarter-inch hole through the wall, using an extension cord from a working outlet.

Switching and connecting the indoor outlet box

You will need to switch the old outlet box for one of the metal gang boxes. Begin by punching out the a pre-scored hole in the back and bottom of the metal gang box. Attach a conduit connector to the back opening of the box, then secure the gang box inside the wall with the screws or nails supplied.

Next, measure the distance from the back of the gang box to the outside wall, and add one inch. Cut a piece of conduit to that length, attach it to the connector on the back of the gang box, and push it through the wall. Attach a ninety-degree elbow connector to the outside end of the conduit.

Next, you will insert the end of your new wire into the conduit from the outside until it is inside the gang box. Pull it through and use the wire stripper to strip one inch of insulation from the three wires inside the wire sheath.

Connect the original indoor wires to the left side of the old outlet, and the new wires to the right side, black wire to gold terminal, white wire to silver terminal, and green or copper wire to green grounding screw.

Adding the new box: outside the home

Outside the house, you will cut the conduit to the length required to reach your intended location. When adding lengths of conduit and connectors, remember to pull the wire through before making connections. 

When you've reached the intended location, punch out the pre-scored hole on the bottom of the second gang box and add a conduit connector. Run the wire through the hole. then cut the wire, leaving about eight inches of wire for connection.

Strip the insulation from the wire ends as it was performed for the indoor connection, and connect the wires to the top "load" section of your GFCI outlet. attach black wire to gold terminal, white to silver, and green or copper to the green ground terminal.

Screw the GFCI outlet into the gang box with the provided screws, and screw the outlet into the wall. Turn on the circuit breaker.

Optional: You may choose to apply a bead of silicone caulk around the perimeter of the gang box to avoid leaks in areas exposed to wind and rain. You may also choose to add an outdoor outlet cover, which protects the outlet from inclement weather.

When you first install a GFCI outlet, it may be in protected mode. Simply push the reset button in the center and you're ready for the holiday lights.

For further assistance, contact local professionals, such as those from Williams Electric Supply.