In my bathroom there are two switches for one light so you can turn the light on/off from either switch. One failed and so I had to replace it. But before doing so I took a picture and noted that all wires are red with the green and black enclosed in a red sheath.

I thought it might be a special switch so off to Bunnings to ask. Nobody knew so I went to Mitre10 and they are equally clueless but having made the trip out, bought a single throw switch. I noted the original switch had connections marked (1), common and (2) all connected (common is the actual red wire in the photo above) with loop not connected. So in the new switch I wired it the same way, with all wires as before and the red wire wired to Common. To my relief but I am not entirely sure how it works.

I looks the original sparky fed two live wires down to the outlet but I can't work out how it works apart from that. Anybody with ideas on how this works?