If you installing TV cabinet, hide the socket and put the extension socket inside the cabinet.

Cause all your player will be inside the cabinet. TV wire plug and other direct into the cabinet socket. That will look nice at neatly. This way also don't need to hack anything.

Regarding how to switch ON/OFF, wire a ON/OFF switch out from the cabinet and put at any cabinet wall that convenience.

This is what I do.

Than just hack la. Provided it is not condo.

Teach you another way. Put another fake plaster wall infront the wall.

Than you can place wire and hundred of wall socket as you want.

Got money? get an ID to design it more artistic.