While I was drilling holes for a shelf unit I encountered sparking from one of the holes. Later when I was re-drilling the same hole with a slightly bigger drill piece I got an electric shock from the drill.
The wall in question is an upstairs brick party-wall between two houses, so stud detectors will be no use, and there isn't a plug or light socket on this wall in this particular wall, though there are 2 other switches further along this wall in the toilet and on the landing (which are both lower than the shelving unit and whose wires come from directly below and go diretly above to the fittings). The room above is an unconverted loft whose power seems to come from a plug socket and is wired externally (though I've not been able to fully check up there).
I've just recently moved into this property and so am unable to fully know the location of all wires. I'll try and contact the previous owner on that point as the place was rewired when he was owner.
I'm a bit paranoid (and worried sick!) that I've hit a power cable. I thought I felt a minor shock by touching the wall, but using a voltmeter against the wall shows no trace of escaping power. Also the socket circuit didn't cut out when the drill sent out a shock.
Is there any other way for drill to shock/spark like this? Any help will be appreciated.
Sorry for the long post.