This is not a commercial - but X-10 sells switches that replace the wall toggle switches, and plugs for e.g. table lamps, so you can turn on all the lights you have X-10 switches on, whatever circuit they are on. Not very costly or involved, and you don't have to rip into the wiring to have control of whatever lights you wish.
Probably there are other companies that sell this kind of stuff, it has been around at least 20 years I know of. I use them, like them, dislike the X-10 web site (it is full of images and loads slowly, and is garish and short on nitty-gritty detail on how the equipment works / is to be employed).
Just my 2¢ - you may find it useful or not.