I have replaced the fuse wire (5A) in the fusebox three/four times now for the upstairs lights after it went a week ago. Once replaceed, all lights work for several hours (the same evening, say) but are no longer working by the following morning, when the fuse wire needs replacing again. Lights never actually stop working while they are on but just won't come on once switched off (usually the next morning). I would appreciate any thoughts/advice on this. The big mystery to me is why the circuit can work for several hours but not indefinitely.