How To Add An Outside Outlet For Your Holiday Lights

If you're tired of running extension cords from inside your home to power your holiday light displays, it's relatively simple to run an outdoor outlet from an existing indoor outlet. 

What you will need:

A GFCI outlet

This is a type of outlet that is designed for potentially wet locations. It will shut off automatically if the danger of improper grounding from damp or wet conditions is present. 

Two outdoor gang boxes 

These are electrical outlet boxes. One will hold your GFCI outlet outside. The other will be used to replace the indoor outlet box from which you will power your new outdoor outlet. You need two in order to run electrical conduit between them to keep your wiring safe and dry.

Electrical conduit and fittings

This is tubing through which your wire will run. Half inch conduit will be sufficient. You will also need a pack of half inch gang box connectors and ninety degree elbows. Measure the distance through your wall from the indoor source outlet to the outside, then the horizontal and vertical distance from that location to the desired location of your new outlet. Buy enough conduit to exceed that distance by several feet to allow for error or changes in direction.


You will need to check the breaker that controls power to your indoor outlet. If it is stamped "15," you will need at least fourteen gauge wire. If stamped "20," twelve gauge wire is required. 


  • Flat and Philips head screwdrivers
  • Hacksaw
  • Hammer drill (you can rent one at a home improvement store) and a three quarter inch masonry bit
  • Wire cutter/stripper

Installing your new outlet: indoor work

You will first need to turn off the breaker that controls your indoor source outlet. When you are certain that the power is off, remove the cover plate and outlet by removing the screws that hold them. Pull the outlet from the outlet box and disconnect the three wires from the terminals by loosening the screws. Remove the outlet box from the wall by loosening the screws that secure it.

Using the hammer drill, drill a hole through the wall in the center of the opening. When you have reached the outside, measure the distance through the wall and cut a piece of conduit with your hacksaw using the resulting measurement.

Attach an outlet connector to one of the outdoor gang boxes by screwing the threads into the hole in the back of the box. Attach the cut piece of conduit to the connector with the screws provided, and push the conduit through the wall.

Attach the gang box inside the wall with the screws provided, then go outside and cut the conduit until it protrudes about one inch from the wall. Back inside, begin to feed your wire through the indoor gang box and the conduit.

Installing the outdoor outlet: outside work

When the wire is through the wall, add a ninety degree elbow to the end of the conduit with the attached screws and pull the wire through. Cut a length of conduit that matches the horizontal distance from that location to that of the new outlet. Feed the wire through that piece of conduit until the end appears, and attach the end of the conduit to the ninety degree elbow at the wall.

Add a ninety degree elbow (pointing up) to the other end of the conduit, and cut a piece of conduit to match the vertical distance from the ground to the desired height of the new outlet. Pull the wire through that length of conduit, and attach it to the upper end of the ninety degree elbow at ground level.

Attach a gang box connector to the other end of the conduit, and attach the other gang box to the connector by screwing it on from the opening on the bottom of the gang box. Pull the wire through the gang box, and secure the box to the wall with screws.

Separate the three wires within the wire sheath and remove one inch of insulation from the end of each wire with the wire stripper. Attach the wires to the GFCI outlet's top "load" side. The black wire will be hooked around the the gold screw terminal, the white wire to the silver terminal, and the green or copper wire to the green terminal.

Screw the GFCI outlet into the gang box with the provided screws.

Back inside the house: finishing the installation

Cut the wire sheath so that at least six inches protrudes from the indoor gang box. Prepare the ends of the wires and connect them to the top portion of the old outlet as you connected the GFCI outlet. 

Replace the cover plate, and you're finished the installation. Turn on the breaker and test the new outlet. It may be in protected mode, so if it doesn't work, push the reset button in the middle of the outlet.

You should consider a flip-up cover for the outdoor outlet if it is in an exposed location, and you may want to apply a bead of silicone sealant around the edge of the outdoor gang box to minimize the possibility of water entering the wall.

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