Performing an EMR assessment I detected and grounded a huge electric field. It was located in the bedroom wall and radiating several feet into the room.  At 464 V/m the client was motivated to investigate and mitigate. He opened the wall to expose the one ROMEX cable inside. There was no physical damage to the cable, but at the one point the field strength was huge. We created a quick fix by wrapping the offending section in metal screen, crimping on a piece of 14 gauge wire and connecting into the circuit ground. We dropped from 464 to 5 V/m. I would call that a successful reduction.  99%