In article .com, no--
says...
I want to put two single width (85mm) BS3676 switch plates side-by-side
on a wall.

I understand that a flush-mounting, 35mm deep metal back box is
available which is just a bit bigger than a double width back box and
has a metal strip down the centre of the opening. This strip has
mounting holes so that two 85mm plates can be mounted flush together.

Anybody know who is the manufacturer of this type of back box? Or can
anyone give me a part number and source, please?



You should be able to get this from any decent electrical wholesaler, and
probably even B&Q. Most of the manufacturers make them - the only thing
to watch out for is that some of them are only spaced for standard white
accessories, and if you want to fit some of the decorative plates, they
will overlap at the edges. The Appleby ones that I use have a wider
centre strip which helps overcome this, but then has the downside that
for white plates there is a small gap between them! If you fill / plaster
over the box before fitting the plates though, this is a doddle to
overcome.