Wiring up bathroom mirror.

You could be terribly posh and use grid system bits with cord outlet. But if the mirror is covering the old shaver socket box, not much point.

Don't think I've seen a 2-gang outlet plate, so I suspect drilling a blank one will be required ... presumably changing to a twin backbox and using a single blank and single outlet would be too much fuss for something that's going to be covered up?

A flex outlet or perhaps a 2A 3 pin plug socket combo would be my preferred options.

or

You could probably do it using a grid switch system and blanking modules.

That's what I was proposing.

And that's my thinking!

Can't use either of those, since the backbox is 2-gang, to fit the existing shaver point.

I may have a solution:

In a 3 or 4 module 2 gang grid plate (choose same maker, grid is usually not cross-compatible).

Use 2 or 3 grid blanks for the other positions.

I think I'll just drill a 2G blanking plate!

If you put a knot in the flex, or use a strain-relief grommit, that'll stop the cable pulling out. For the actual connection, a choc block or Wagos are all fine.

I thought that a "knot in the flex" is specifically not allowed as a strain-relief.

My heated illuminated bathroom mirror has a large metal box about 2" deep which screws to the wall and which contains a couple of fluorescent tubes. There is a hole in the back for the cable to come through and a choccy block connector inside. The mirror then attaches to the box after making the connections. There is a heating element on the back of the mirror, with a short cable and plug/socket inside the box.

Isn't yours like that?

Mine replaced a strip light which had a built-in shaver point, and had a cable emerging from under the plaster and connected into the back of the strip light. I needed to re-route and shorten the cable slightly and patch up the plaster - but it was all hidden behind the box.

A variation on Tim's solution; you can get a variety of accessories in euro mod forms:

So fit a double modular frame, and then a module like the above plus a blank in the double gang frame.

I was going to put a cable tie round the cable inside for strain relief and use a Wago. Just wondered if there was a "better" way.

I did something similar. Twin backbox (rather than two gang), with a single blank plate and a single outlet. And cut a cable hole between the two halves of the backbox.

So is the power from the old shaver point enough for a shaver point, heater and leds? I of course do not know how the supply was wired, but I assume you mean that you are just using the incoming wiring not the actual shaver point itself. As its in a bathroom I'd be a little worried about the chocky block approach unless the box is pretty well sealed, though I have to admit in years past I have used these blocks inside patress mounted boxes to get out of trouble which otherwise would mean massive rewiring jobs. Brian

No.

:o)

Inside a backbox a choc block (if of decent quality) is no better or worse than the screw terminals on the back of the socket etc.

Even slightly better. You could overlap the wires so both screws bite into them. Wrap the entire joint in self amalgamating tape. Less chance of moisture then causing problems than with the terminals on a shaver socket. Not that I'd bother, of course. ;-)

Fit a 2 gang blanking plate .. and make connection inside using choccyblock connectors. Fit a cable gland (nylon type) to this for flex exit: