[emeritus]

I think that up in the loft I still have the circa 1938 switches, then over 40 years old, that I removed when I rewired our house. Most of the springs were tired. They were recessed types mounted in wooden boxes recessed into the plaster, and had been shimmed with carboard shims (mostly old fag packets) to align them with the plaster surface for attaching the front plates.. Interestingly, the width of the wooden boxes is the same as the distance between the fixing screws of modern switches snd single sockets, so for the one switch I did not relocate because it was in the tiled wall of the WC (the switches were originally positioned far too high) I was able to fit a modern switch using woodscrews that nicely engaged the wood of the box. Interestingly I have a (late 1950's /1960's ?) MK switch in brown Bakelite that came with both a pair of brown 4BA machine screws and a pair of No6 brown raised countersunk woodscrews, so I wonder if the pre-war wooden boxes were made to a standard size that determined the size of the present metal boxes.