Customer call and said her lightings are blinking, I'm thinking loose neutral in the panel. She driving me crazy. She was having work done on her Dryer and the handy man went to turn braker off and sparks frew out from panel. I checked the bus and one stab was burn bad. The panel was a mess who ever wired it had #14 on 20 amp breakers and a spa wired with # ten romex on 40 amp breaker. Other breakers had two wires on them. I changed all the breakers. I used mini breakers so that each breaker only had one wire. Clean up and thought the panel looked good, put a blank over stab that was burn. Everything worked fine and now a week later she calls and tells her lights are blinking!