The fact the socket is "lighting up" as you stated would lead me to believe that you are overloading the socket. The wiring in the socket should be minimum 2.5 mm and should be protected by a 20Amp fuse or circuit breaker if its a radial circuit or a 32Amp fuse or circuit breaker if its a ring circuit.
It could be that the appliance that you are plugging into the socket is faulty. In any event , be careful. Sockets "lighting up" are dangerous and are a serious fire hazard
Gary
November 2010