Is this right?

[richardrich79]

I have one of the voltage checkers that light up when one probe is touched to the live + and the other to neg - or earth.
Whilst checking the front door light switch I was bemused to find that the probes light comes on when connected to the live wire and the other probe pressed against the interior wall. The house is mid-Victorian lime plaster and no noticeable damp problems however the hallway is unheated.
I should add all the electric circuits have been rewired recently and there are no known problems, nothing tripping etc.
Should I be concerned?

 

[Taylortwocities]

What voltage does your voltage checker say?

What sort of thing is your test device, some of those are not reliable. I have one that lights up if it is near my cell phone..

 

[seasickstevie]

If you use a neon screwdriver to check if a wire is 'live', you only touch one wire with it and it should light up.
That's because a very small current is passing through you and into the ground, completing the circuit.

It's not uncommon when in a dry atmosphere on say the first floor, standing on carpet that you might find a neon screwdriver won't light up when touching a live wire. If you then touch the wall with your other hand, it lights up.

That's basically what your doing with your 'voltage checker', your completing the circuit to earth.

 

[Taylortwocities]

It sounds like he has two probes though, one on the bell wire and one on the wall?

 

[seasickstevie]

... checking the front door light switch

... live + and the other to neg -

I assumed it's the colloquialism '+' & 'neg' that's used by some meaning Live and Neutral

 

[Taylortwocities]

I am expecting that this door bell does not have 230v AC at the push button!

 

[ban-all-sheds]

Anybody have a clue why TTC is talking about doorbells?

 

[wingcoax]

Got his wires crossed?

 

[richardrich79]

The tester has 2 'probes' connected by a wire, 1 red with 3 lights that are labeled 110, 220, 300, the other probe being black.
When the red is in contact with a live wire and the black either to the neg or earth wire the 220 light lights up. In the case of my houshold supply the 110, 220 are bright and the 300 'glows'.
I do not use the probe for anything other than making sure that the power is off.
I'm guessing that the wall has some dampness and that's why the single 110 light glows when connected to the brown wire on the light switch and the black probe stabbed into the wall. The moment I touch the black probe to an earthing point the 2nd light comes on.
I would post a photo by the camera on my phone has stopped working.
It is the single pole light switch not a doorbell btw

 

[Taylortwocities]

Arghhhhhhh. Ignore my post please

I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly

 

[richardrich79]

My tester is similar to this https://www.machinemart.co.uk/shop/product/details/draper-vt2-acdc-voltage-tester
I have checked & it does work correctly and only the hall wall gives a reading.

 

[seasickstevie]

... and only the hall wall gives a reading.

I'm assuming your hall wall is masonry, and other walls you've tried are internal and perhaps either studded partitions or dry-lined.

You're far less likely to get an earth through plasterboard.

 

[richardrich79]

Thanks for the reply, all the walls are lime plaster over brick and stone. There is no plasterboard in the ground floor. am I right in thinking that the fact the walls 'earth' is not a serious problem?
I've tested the walls with a specialist damp-meter and there is no cause for concern there.

 

[Taylortwocities]

It may not be damp, but it will be "earthy". Especially lime plaster, as it tends to breathe in moisture.

Your tester will be a very high impedance, so one of the LED indicators will come on with only a tiny current flowing. Nothing to worry about IMO.

 

[conny]

Arghhhhhhh. Ignore my post please

I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly
I must learn to read the posts properly

I hope you didn't copy and paste after the first line?