Well, it is not so much of a problem as just strange. I have had my brother, who knows a bit about power circuits, do some testing on my current house, and it s

Well, it is not so much of a problem as just strange. I have had my brother, who knows a bit about power circuits, do some testing on my current house, and it seems OK. But sometimes, and only sometimes, metal shell things plugged into the UK mains via 3-pin UK plugs will do the throbbing stuff. And as I said, this happened in multiple houses, with multiple PSUs and laptops and other stuff. I dunno.