Not an electrician ! Have changed most lights in the house no problem changed hallway light recently but now when we switch it on bathroom and kids bedroom lights go off if they are on halway bit confusing as to why if anyone could help me thx downstairs hall has double switch for upstairs spots on landing and hallway chandelier upstairs only has one switch single switch which turns spots off not sure if this is supposed to be a double as well and may be.my problem or if it's a 2 gang 2 way prob which I'm not sure what their true meaning is !!!!