Been visiting my parents for a week, as usual did a few jobs around the place for them.
One was to fit an old kitchen cupboard on the wall in the new utility room.
Hold cupboard up on the wall deciding where they want it, I comment it needs to be high enough to give access to the sockets and FCU's below.
Decide on placing, mark out and drill the first hole for the fixing screws, drill goes off line a bit.. Peer into hole, notice something shiny - realise it's the exposed live conductor of the ring main feeding the above mentioned sockets etc.........
The question is - where was my brain at the time? It's not like I'm new to this game, or that I didn't know they were there, or do not know to check that sort of thing.............