Light switch and earthing

[rdejones]

I recently brought a new touch switch with a remote control function on it. I wired it into the old switch point which is a plastic one (plasterboard walls). I correctly earthed it for this, putting the sleaved earth directly into the switch earthing point.
The switch worked fine but I became conscious that the button, although not the metal around it to which the earth was connected, gave the slightest of tingles when I touched it. Worried by this I tried it in three other locations (including the switch closest to the distribution board) but got the same effect. I checked the earth cables in the light fittings but none seemed loose (although this was far from a thorough check.
For the mean time I have gone back to plastic but it left me wondering whether this was how these touch switches worked (through a very small amount of current passed through the person) or whether I have an earthing problem on the circuit.
What do people know or think?

 

[securespark]

You need a multimeter to check the supply to the switches and continuity of the cpc.

 

[Steve]

They work by detecting capacitance. Whatever that is.

I had one of these switches, but it was plastic surround, and i never got a tingle or anything off it.

A multimeter may be handy to diagnose the problem.

Assuming its a varilight, try emailing them.

 

[slup]

Some work by capacitance, others are much simpler.

The Varilight ones for example actually just have a couple of 2M ohm resistors in series with the button. The button is actually at mains potential if you put a meter between it and the faceplate.

So getting a tingle off them is pretty normal. The OP said he wasn't getting a tingle from the faceplate, just the button.

Steve