Ive got an apartment with 3 bathrooms all on 1 fan which is on permanently, they want to be able to switch on a light in each individual room and the fan but go off when the light goes off too. is there a relay or contactor that will take 3 diferent supplies but not backfeed to the lights in the other rooms, or a way of wiring it. thinking of 3 feeds from each room light to 3 separate relays controlling a parallel feed to the fan, any ideas otherwise or better. All lights and fan on same circuit 240v.