Hi all. We only have upstairs lighting in the bathroom. Until recently our lights upstairs worked apart from the bathroom. I checked the wiring on the bathroom light fitting and pull switch. Found loose wiring at the fitting, reattached it and now the rest of the lights won't come on. My nephew is a trainee electrician and has checked all light fittings, switches and light bulbs. Power going to each one but still won't come on. Old style wiring in the house. I think it's to do with the wiring at the pull switch and/or bathroom light fittings. Can anyone help me with this problem please?