I've got a 500w floodlight on the external rear wall. A light of some description has been there for several years without any issue. More recently when the light is on for a while (anything from 30 to 90 mins), it trips the circuit. The floodlight was swapped for another one so I can rule out the unit. The wiring is in the loft and would take a considerable amount of work to get to. Just want to do the basics before getting a sparky in. Is it likely the switch could be causing it to trip after bring switched on for a while? Cheers.