Brian Gaff wrote

Hmm, cannot see that myself. Without screening and stuff like that switch
impulses will just radiate in my experience.

Its not clear that he is actually talking about switching transients,
more likely he's just talking about mains frequency hum, but that
doesn’t happen enough to matter with lights.

"DICEGEORGE" wrote in message
...
I seem to recall reading somewhere that in 2 way switching for house
lighting its a good idea to have a neutral wire parallel to the lives to
cut down on interference, is this so? In which case I need 4 core and
earth not 3 core and earth.

I is mentioned at:
http://wiki.diyfaq.org.uk/index.php/2_Way_Switching

[g]