On 20/01/2019 14:47, Dave Plowman (News) wrote:
In article ,
wrote:
I've just found a better solution to this particular problem. There's a
light switch in the adjacent room, almost exactly behind the switch
that's bothering me, and this has an earth. They are on the same
lighting circuit so an earth wire through the wall and all is well.

Do check the earth is connected to earth, though. In the days when earths
weren't mandatory but TW&E was around, you'd often fine it connected at
one end, but not the other...

A very good point, but I had checked and there *is* continuity.