I got these things out of interest when I got petrol, only a fiver for three at Morrisons.
http://www.ecosavers.nl/?page_id=126
Very handy for switching awkward to access switches on and off.
Now I walk in and switch everything on remotely.
Even better, if something goes dangerously wrong on the lathe I can run away and switch it off remotely from a safe distance…not that anything ever will…I’m much too good for that…