The VoltAlert AC non-contact voltage testers from Fluke are easy to use — just touch the tip to a terminal strip, outlet, or supply cable. When the tip glows red and the unit beeps, you know there’s voltage present.
These are available on Amazon France for around 30 euros including delivery, click the link below.
Been using one for years. Good tool but beware if you are testing a bunch of cables as it can easily pick up 'stray' voltage. Easy to test for socket polarity with a gadget like this but no substitute for a multimeter. Test them on a known live source before trusting them as a 'knock' can dislodge the very fine wire inside which connects to the battery -ve. meaning it won't light up & you might blow yer frock off ;-)