Unless you have a safe way of identifying what the wires are connected to at the other end it is not possible to advise you what to do other than to call a competent person who can check for you. The problem arises because there is not a definitive way of wiring lights, and as such is down to who ever installed the cables as to what each one does, it is possible to guess, but to guess is never a good idea.
DIY how to tutorial projects and guides - Did you know we have a DIY Projects section? Well, if no, then we certainly do! Within this area of our site have literally hundreds of how-to guides and tutorials that cover a huge range of home improvement tasks. Each page also comes with pictures and a video to make completing those jobs even easier!