Should these only 'light' when making contact to a 'live' (meaning positive, usually red) cable ? When making contact to the neutral, should there be no light at all, not even a glimmer ?

Thanks.

Assuming you mean a neon screwdriver of the type where you put your finger on the end.

In contact with the Live (no it's not Positive and it's usually Black in Thailand) the neon will glow, in contact with the Neutral (White) or Earth (Green) it will not.

NOTE. If you touch a floating wire (such as a switched live that is turned off) you may see a glow, this is caused by stray current being picked up by the wire you're touching (capacitive coupling).

It is important to note that these devices should not be used to 'prove dead', by far the safest way to ensure a circuit is dead is to open your main incoming breaker.

Assuming you mean a neon screwdriver of the type where you put your finger on the end.

In contact with the Live (no it's not Positive and it's usually Black in Thailand) the neon will glow, in contact with the Neutral (White) or Earth (Green) it will not.

NOTE. If you touch a floating wire (such as a switched live that is turned off) you may see a glow, this is caused by stray current being picked up by the wire you're touching (capacitive coupling).

It is important to note that these devices should not be used to 'prove dead', by far the safest way to ensure a circuit is dead is to open your main incoming breaker.

when i was much younger and very much dumber i used to wet a finger and touch a wire to find out "dead or alive".

Assuming you mean a neon screwdriver of the type where you put your finger on the end.

In contact with the Live (no it's not Positive and it's usually Black in Thailand) the neon will glow, in contact with the Neutral (White) or Earth (Green) it will not.

NOTE. If you touch a floating wire (such as a switched live that is turned off) you may see a glow, this is caused by stray current being picked up by the wire you're touching (capacitive coupling).

It is important to note that these devices should not be used to 'prove dead', by far the safest way to ensure a circuit is dead is to open your main incoming breaker.

when i was much younger and very much dumber i used to wet a finger and touch a wire to find out "dead or alive".

I use to get someone else to do that for me.

ye can get a cheap multimeter and hook it up to see what ye get without havin' to touch nothin...just some alligator clips...the little pencil devices were always good for car electrical systems but no good fer home use...useta use 'em for the timing on the old VWs...