Several years ago I had an idea to have one switch that would kill power to the entire layout. Finally got around to it. last night my electrician stopped by to finish a small project in the kitchen and had him tackle my kill switch for me.
I have four outlets in the basement for the layout, one for the main power supply and command station, two others where the circuit breakers for the layout are plugged into and one for the lights over Malvern.
So now with one flick of the switch, as AC/DC would say, the layout is on or off. I took it one step further and had him add an outlet so when the stormy weather arrives in the spring and summer and there's bad storm coming, I can not only shut it off, I can also pull the plug and the entire layout is now unplugged from the rest of the house.
Not that this will be a sure thing if I get a good lightning strike, but it improves the odds of not having a bunch of puddles around the layout where my chipped locos were sitting or end up with a fried command station. It's more of a piece of mind than anything.