I got some trouble with our wiring. When I worked on some circuits of our late 1970ies-panel I inadvertently touched the ground bus with the back of my hand and got a nice shock. When i pulled out the dishwasher ground wire it sparked heavily. No other ground wire did that. There's definitely quite an amount of juice flowing in the ground, but neither the old 100mA nor the new 30mA RCD have tripped.
Can you give me any help here? When I threw the dishwasher breaker (1+N) the arcing stopped as well.
