How to Safely Install an Electrical Outlet

A photo of a breaker being shut off.
Turning Off a Breaker - Photo. Timothy Thiele
Overview
  • Total Time: 30 mins
  • Skill Level: Intermediate

Most homes could use an additional outlet (or twelve) to their existing walls. If your home is among the many older homes with very few outlets in each room, why not add a few outlets, often called receptacles, to make the room a little more convenient? In this article, you'll learn how to add another outlet in an existing wall. These easy steps can be accomplished without damaging the portion of the wall that you see.

3:40

Watch Now: How to Wire and Install an Outlet

What You'll Need

Equipment / Tools

  • Pencil
  • Razor knife
  • Putty knife
  • Drywall saw
  • Drill
  • 3/4" paddle bit or auger bit

Materials

  • Fish tape or a scrap piece of wire
  • 12-2 NM (Romex)
  • Drywall screw

Instructions

  1. Turn off the Power

    We all need to install an outlet in an existing wall from time to time. It may be that we've moved a bed, couch, or added an appliance to a wall where there is an outlet too far away or there just isn't one on that section of wall where it is now needed. As with any other electrical project, turn off the power to the circuit that you'll be working on. To do this, use a tester or plug something into the outlet. Go to the breaker or fuse panel and turn the circuit off that feeds the outlet. When the tester light goes out or the buzzing stops, the circuit is off and you have disconnected power from that circuit.

    A photo of a breaker being turned off.
    Turn Power Off. Timothy Thiele
  2. Prep the Area

    To install an outlet to an existing wall, the next step is prepping the area. Before starting the project, face the wall that needs another outlet. Clear everything away from the wall that you'll be working on. Locate the base trim and with a pencil, lightly mark the top edge of the base trim so that it leaves a mark on the drywall. This will be the area of the wall face that will be removed to access the wall cavity. Marking the area will allow an easy line to follow to make a cut into the wall and allow you the ability to cover the affected area up afterwards so that no one is the wiser that anything had ever been done.

    A photo of an empty wall.
    Empty Wall. Timothy Thiele
  3. Remove the Base Trim

    The third step is to remove the base trim. Use a razor knife to break loose any paint that may be attached where the wall and trim meet. Yours may not have this problem, but I've listed it just in the event you do. 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.

    A photo of trim being removed.
    Trim Being Removed. Timothy Thiele
  4. Cut the Drywall

    Using a drywall saw, cut just below the pencil mark that you just marked on the wall. Be careful not to cut too deep and 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.

    A photo of a drywall saw cutting drywall.
    A photo of a drywall saw cutting drywall. Timothy Thiele
  5. 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.

    A photo of holes being drilled in the studs.
    Drilling Holes in the Studs. Timothy Thiele
  6. 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 six to seven inches from the end of the wire. Remove the lock nut for now. You will need it later.

    A photo of wire being fed through the wall.
    Feed Wire Through the Wall. Timothy Thiele
  7. 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.

    A photo of a wire being installed in a box.
    Wire Being Installed in a Box. Timothy Thiele
  8. 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.

    A photo of a box being marked for a cut.
    Mark a Box for a Cut. Timothy Thiele
  9. Install the Cut-in Box

    Using the drywall saw, cut the drywall and remove the scrap. Knock the bottom knockout out 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.

    Drill the Studs
    Drill the Studs. Timothy Thiele
  10. Feed Wire to 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 six inches into the box.

    A photo of a wire being installed in a box.
    Install a Wire in a Box. Timothy Thiele
  11. Install Drywall and Trim

    Using a drywall screw, reinstall the drywall piece that you earlier cut out. Reinstall the base trim and what do you know? The project is complete and you wouldn't even know that anything had been done. Well, except for a little vacuuming that may need to be done.

  12. 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.

    A photo of wires being connected.
    Connect Wires. Timothy Thiele
  13. Connect 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.

    A photo of a pigatil connection.
    Pigtail Connection. Timothy Thiele
  14. 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. It is as easy and painless as that and you'll have everyone wondering how you did it!

    A photo of a breaker being turned on.
    Turn Breaker On. Timothy Thiele