Wall Light Switching

for wall lighting is it acceptable to run a cable from the existing lighting Circuit to a switch then to a wall light, rather than using a junction box for switching in the roof void.

Yes, this is generally fine, providing the earth and neutral cores are carried through the switch box on proper terminals (or crimped and sleeved -the problem is that single pole switches don't normally have the extra terminals for the neutral, although a nicely fitted choc block is usually accepted, but a deeper back box than the minimum will be needed to do this neatly..) .
All the usual rules about cables following "the line of least surprise" (i.e. only wire horizontally or vertically to fttings and switches, or protect with earthed conduit or trunking) are still appropriate, more so if there is a risk of picture hooks piercing buried wiring.
The only other common way to do it is to take fused spur off the ring main below, if the wiring for the lights above is too hard to get to.
M.

thanks for info mapj1

mapj1 said:

the problem is that single pole switches don't normally have the extra terminals for the neutral

Click to expand...

Do they ever?

why cut the neutral in the first place?

Good point.

-OK I was being sloppy. Many single pole fused switch units have a neutral terminal, as per the spur from ring main job. Normal light switches don't, I agree.
M.