if I'm planning to install a wall mounted TV cabinet for AV system,
where do I position the power sockets on wall? I want the cabinet to
conceal all the wall socket and also the wires.

Another question is, if the cabinet were to conceal the power socket,
is it going to be hard to switch on/off for individual sockets?

initially to overcome this, I planned to install a 1 Gang switch to control
all the multiple power sockets.. good or bad idea?