This a simple topic and one which may be of no value if you have a tiny layout. In my case, with a layout running around the walls, I had 3 mains power outlets all of which would be difficult to access when the layout construction was under way. This is one of a number that are available which come with remote controller (shown below) to switch varying number of outlets. This one does the job for me. Check on-line for pricing (look up: remote control power outlet)