Dear Mr. Electrician: I want to install an electrical outlet on a dedicated circuit for my window air conditioner. I’ve got it figured out how to run the 12/2 NM-B cable from the circuit breaker electrical panel in the basement up through the wall under the living room window. How do I install an electrical receptacle box in the wall that will contain the wire and support the receptacle?
Answer: The hole above was made using a drywall saw. The metal outlet box was held against the wall and a pencil line was traced onto the surface. Note the notches on the upper right and lower left corners. They are to allow for the protruding screws on each side that all metal receptacle boxes of this type have.
Click here for my post about installing an electrical receptacle.