StarDreamer
I am wondering if there is such a thing as a self-contained unit that plugs directly into a mains socket that emits light when the mains switch is switched on.
So no cables or needing to stand a lamp unit somewhere.
I have looked on the web and thus far as far as I can tell I have only found one that just has a neon indicator so that one can test if a socket has power being fed to it.
The problem is I don't know what such an item, if available, would be called, so I cannot search for it easily. I have tried various things.
We had a small green lamp on bord our boat that came on when the shore power line was plugged in, when we were staying in marinas, if that is the power was on in the marina.
I have not the faintest inkling of what it was called, we bought it in Nijmegem at a very well-assorted electrician's shop.
So after the weekend, perhaps you should phone an electrician and ask.
If you need it because some of your power sockets are at bit dicy, you should really get them checked by an electrician.