What’s going on here?

[NRS]

I unscrewed an old plastic face plate to fit a new modern metal one and got more than I bargained for.

There is no back box. And we have a 2 way switch when this switch could only ever control one light. I can’t work out where the second cable comes from.

Can anyone advise me?

 

[EFLImpudence]

There is no back box.

What do you think the screws screwed into.

And we have a 2 way switch when this switch could only ever control one light. I can’t work out where the second cable comes from.

Maybe there used to be two switches operating the light.

Can anyone advise me?

Make sure you earth your new metal face plate.

 

[NRS]

I think they are screwed into a scrappy bit of wood.

So I guess one cable is redundant and can be terminated?

Absolutely will be earthing the new metal faceplate

 

[ericmark]

I noted my parents old house back box was wood, with Wylex printed on it, so not a DIY thing, and two red and a black wire could switch two lights.

 

[Harry Bloomfield]

and two red and a black wire could switch two lights.

The two wires, black and red, at the same end of the switch, could equally be strappers - which suggests it is a 2-way system, with a second switch located somewhere.

 

[Harry Bloomfield]

I unscrewed an old plastic face plate to fit a new modern metal one and got more than I bargained for.

What probably happened, was....

In the dim and distant past, post 1960 judging by the fact that an earth seemed to be included, the lighting circuit was rewired, reusing the old conduit and timber box set in the wall - to avoid damaging the wall decoration. Timber boxes, and conduits in walls, predate 1950.

Your easiest fix, is to buy a suitable depth of metal box, try to break out the timber box, and set the new box in its stead.

 

[mikeyd]

So I guess one cable is redundant and can be terminated?

No. Unfortunately not.

You need to find the other end of that cable.

 

[JohnW2]

What do you think the screws screwed into.

It looks as if the faceplate screws were screwed into a couple of studs which, in turn, are screwed into something behind. However, the nearest to a 'back box' seems to be some rotting wood with (I think, but I am not certain) no obvious back.

 

[Murdochcat]

I think the installation should be inspected properly

 

[Harry Bloomfield]

However, the nearest to a 'back box' seems to be some rotting wood with (I think, but I am not certain) no obvious back.

I can see a back, but the top of the box has been broken away, probably to access the end of the conduit.

 

[SUNRAY]

What probably happened, was....

In the dim and distant past, post 1960 judging by the fact that an earth seemed to be included, the lighting circuit was rewired, reusing the old conduit and timber box set in the wall - to avoid damaging the wall decoration. Timber boxes, and conduits in walls, predate 1950.

Your easiest fix, is to buy a suitable depth of metal box, try to break out the timber box, and set the new box in its stead.

I have wooden backboxes in my 1968 house

And This was another about the same age

 

[securespark]

In my experience, the wood is a ply wooden back box with dovetail joints. Originally, the faceplate screws would have been woodscrews that would have been driven straight into the backbox.

It has been butchered a tad at the top to let in the cables. I can't tell if that is capping or conduit.
The original switch drop could, of course, have been altered to make a two way.

In my experience, I have seen both wooden and metal back boxes from houses built in the 50s. The metal ones were standard size, but with fixed lugs and manufactured of very much thicker metal than today's efforts! Also the 50s boxes were black japanned.

I have also seen a different style of light switch in the early 90s, a bit like a 4 gang but portrait instead of landscape and slimmer. I can't for the life of me remember the brand. IIRC, I only ever saw them in 30s houses in Sale Moor, M23. They had wooden back boxes.
It was similar to this, but not the same.

Back to the cables in these switches. The conductors are not tinned, so I don't think they are imperial. The sleeving predates 1978.

I have known houses to be rewired, but the lazy beggers leave the old wooden boxes in!

I've even seen rewires where the spark used Ashley sockets (going back to the 80s) and 16mm lighting back boxes.

Can't believe he crammed it all in...

I have wooden backboxes in my 1968 house

Can't believe that!
Maybe he had leftover stock?
I had a house built in 1968 and it had metal back boxes, cpcs to the lighting and a TN-C-S intake.

Surely not compliant with the 14th Ed, then! I'm positive that wood had gone out by then. I "grew up" on the 14th as, although the 15th was technically issued in 1981, it wasn't compulsory until 1985, hence why VO ELCBs were deleted from the regs in that year.

I also worked for a chap who was still stuck in the 14th Ed when the 16th came along!