In our current gaff we have a shower pump to boost two feeble showers.
The pump has taken to running for a couple of seconds a few times a day for no obvious reason, or maybe there was a good reason because I've just seen this damp/wet patch (I poked the little hole in the centre) :
This damp patch is probably in line with the plumbing to one of the showers so I'm guessing that's the culprit. It's tiled above, so I'm about to cut a big hole in the ceiling to try and find out what the problem is.
My good lady suggested that I seek your (collective) wise council before I set about it with my multi tool.
What's the best way to attack this?