This bus has discoloration at it. There are multiple double tapped neutrals and at least one triple tapped neutral here. Also a ground tapped in that is not factory original. Would the neutrals be the likely culprit? Just trying to learn more. Is this due to heat or another ocurrence?
Home is pre 1920, knob and tube but all the panels and much of the wiring had been updated. Active knob observed in attic and no ground wires at any receptacles so likely still in many places.