How to Safely Install an Electrical Outlet

Remove the Base Trim

Use a razor knife to break loose any paint that may be attached where the wall and trim meet. Use a putty knife to loosen the trim from the wall and then use a flat bar to remove the trim. Push the flat bar down between the wall and the trim. Pull away from the wall with the flat bar the entire length of the trim. Set the trim aside for now.

Cut the Drywall

Using a drywall saw, cut just below the pencil mark on the wall. Be careful not to cut too deep, as you could cut a wire hidden behind the drywall. Carefully pull the piece of cut drywall away from the wall. Set it aside so that you can reinstall it later.

Drill the Studs

Using a drill and a 3/4" paddle bit or auger bit, drill holes in the center of the 2x4s, just above the plate. Do this from the existing outlet to the location where you'd like the new outlet.

Add the Wire

Install 12-2 NM (Romex) through the holes that you drilled. Leave some slack at each end for adjustments later. If your box requires a Romex connector, add it now about 6 to 7 inches from the end of the wire.

Remove the lock nut for now. You will need it later.

Feed the Wire to a Box

From the existing box, take the knockout out of the bottom of the box. Feed a fish tape or a scrap piece of wire through the hole until you see it in the opening that you cut below. Attach the Romex to it with electrical tape and pull it through the hole in the box. Attach the lock nut and secure it with a tap on a screwdriver.

Mark the New Outlet

Take a tape measure and measure the top of the existing outlet. Now mark the new outlet the same. Use a pencil and a level to align and mark the new cut-in box.

Install the Cut-in Box

Using the drywall saw, cut the drywall and remove the scrap. Knock out the bottom knockout of the cut-in box, so that you'll be able to insert the wire. Now, install the box and tighten the side straps or add Madison straps to hold the box in place.

Feed Wire to the Cut-in Box

Feed a fish tape or a scrap piece of wire through the hole until you see it in the opening that you cut below. Attach the Romex to it with electrical tape and pull it through the hole in the box. Attach the lock nut and secure it with a tap on a screwdriver. Your box may have its own wire strap. If so, tighten it once the wire is pulled at least 6 inches into the box.

Install Drywall and Trim

Using a drywall screw, reinstall the drywall piece that you earlier cut out. Reinstall the base trim. Now it's time to vacuum up any evidence.

Connect the New Outlet

Strip the outer coating from the Romex and strip the black and white wires about 3/4 inch. Bend a half-moon and wrap the black wire clockwise around the brass-colored screw. The white wire is next and it is attached similarly, only to the silver-colored screw. The bare copper wire connects to the green screw. Tuck the wires into the box and screw the outlet into the box. Install the cover plate and you're finished with this outlet.

Connect the Existing Outlet

The existing outlet will need a pigtail connection. This involves cutting scrap pieces of the three colored wires and attaching one end to the outlet and the other to the two pieces of Romex. Find out how to attach a pigtail.

Attach wire nuts to connect the wires. Gently press the wires into the box and screw the outlet into the box. Install the outlet's cover plates and you have finished the outlet installation.

Turn on Power and Test

The final step is to turn the circuit back on and test the circuit. Be sure to try both the new and the old outlet using your electrical tester.