An overloaded circuit means you have too much demand on one outlet. When your appliances demand too much power from an outlet, that leads to overheating, which could be why you’re seeing that burn mark on your outlet.

What causes a burnt plug socket?

Sometimes outlets are overburdened with appliances, loaded power strips, etc., and the demand is beyond what the electrical wiring was designed to carry. When this happens, the wiring will become hot and possibly ignite or melt anything that comes into contact with it, including the plastic outlet.

Is it safe to use a plug with burnt prongs?

No, it’s unsafe because the burnt part would have lost its insulation property and can give a shock when came with contact.