Remodel boxes (also called cut-in or old-work boxes) clamp to the drywall or plaster rather than attach to a framing member, making the work easier. However, they are only as strong as the wall surface to which they are clamped. If the drywall or plaster is damaged, cut a larger hole and install a box that attaches directly to a stud or joist. Select boxes that meet local codes. For a ceiling fan or a heavy light fixture, buy a fixture box that attaches to a fan-rated brace.
Before cutting a hole, use a stud finder to make sure no joist or stud is in the way.
About 15 minutes to cut a hole and install a remodel box (not including cutting a pathway for the cable and patching walls)
Stud finder, torpedo level, utility knife, screwdriver, hammer, drill, drywall saw (or rotary cutter or jigsaw)
Measuring and cutting drywall
Carefully plan the routes for the cables and the locations for the boxes. Spread a drop cloth or large towel on the floor below.
Remodel boxes acceptable under local code, cable clamps, if needed