Electrical "Leakage" in a tank??

[andsoitgoes]

It's AC, trust me

ANd I can't reach the wet spot on the floor, unless I'm using myself as part of the circuit.

I've unplugged everything, and put it back in once at a time, testing before and after - the SECOND I plug anything in, I get some minor current.

Again - the zap is happening only on the areas I have open cuts on (i was doing work outside and cut the heck out of my fingers)

When I hold the ground with the + in the tank, and stand on the wet spot - It shows on the voltmeter, but a VERY small amount.