The new dishwasher has a shiny metallic shell, presumably some kind of stainless steel. Every time I touch it I get a shock.
Well, every time until a thunderstorm prompted me to climb round the back and unplug the machine[0].
Unplugged -> no more shocks.
Worried now.
[0] There's a long list of kitchen appliances destroyed by surges here, so I unplug things. Please don't tell me it shouldn't happen - that is really not comforting.