Use either a single gang retrofit work box or for new construction installations, use a new nail on box. Once you have wired the receptacle, then begin by inserting the receptacle portion of the plate into the work box. Once the entire recessed plate is flush to the wall, using the two shite screws supplied, screw the receptacle portion of the plate to the work box. Next, screw down the screws with wings. These wings will fasten tightly against the back of the drywall. Plug in all necessary video and audio cables. Install your flat panel TV wall mounting bracket per the flat panel TV bracket manufacturer’s instructions.