Can’t remove light switch socket backplate Ask questions and find answers to many subjects relating to electrics and electrical work

[diycow]

Hi. I’m trying to replace a light switch and have to remove the back plate as it’s an old style that doesn’t fit the new switch (although box dimensions are the same.)

The old back plate has a pipe containing the electrical cable that is screwed into the back plate, which is preventing me from removing it.

Does anybody know to remove it?

[Mr White]

That "Pipe" is conduit. It usually has a coupler screwed onto the end. (Which sits just above the back box) then there is usually a brass bush that screws into the coupler. You undo the bush, which releases the old back box, and install the new box, but the new box will not line up with the old one, you will have to make the hole for the back box bigger. I don't see a brass bush or coupler, must be very old.

Alternatively fit a surface patress over the existing box and put your switch onto this

[ericmark]

Not seen a back box like that for years, the back box is threaded so needs to remove the conduit away from wall to be able to unscrew box.

Personally I would cut up the old box with a multi-tool, or use some other botch to fit new box. Only seen those boxes used where the wall is not plastered and the conduit is surface.