just having a new shower unit put in my old cuboard with the hot and cold coming from the house pipes but i want an extractor fan with a showerlight and a pullswitch the fan is going through to the outside wall but wanted to know if i could use the junction box to connect it all to the light downstairs. the shower light is resessed with a transformer stepping down to a 11.4 v i have no diagrams and would be greatful for your help