Electrical Wiring in the Home/sparking main panel grounding wire
What would cause continuous sparking, fairly large sparks, at a grounding clamp connection from a main panel. Connected to a Col water pipe of painted copper.
This sounds pretty serious. Most likely, there are some loose wires in and around the panel. It is also theoretically possible that the problem is coming from a neighbor's house and the electricity is coming through the metal pipes. If it still sparks after you turn off your main breaker, then it would indicate a neighbor's problem.
This is probably something more than a homeowner can handle, and since it is a fire hazard, I would get an electrician to look at it ASAP.
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