Hi , i have put a small bathroom in at the end of a utility room and want to be able to switch the room light off at the other end where my new bathroom is . I only have a 3 core wire going from the utility light to the new bathroom switch , can i turn on the utility light anyway and also turn on my new bathroom light , do i need two different switches , can i use power from bathroom switch to run up the 3 core wire to turn it on . Any help please will be really welcome . Sean