The incident occured this morning (13 Sept 13)at 01:57 in a property on Kings Road in Harrogate.
The damage was confined to the socket and surrounding cavity wall insulation and plasterboard.
Crews used a dry powder extinguisher and a thermal imaging camera to ensure the fire was out.
A man suffered minor burns to his fingers and was initially treated by fire crews before being taken to hospital by ambulance for further treatment.
The cause of the fire is believed to be defective electrics in the socket.