Haha I have a good story about getting off with red light tickets.
My wife's boss and his girlfriend drive to work and home every day to the city. They randomly take turns driving, no set pattern. Their vehicle was flashed by a red light camera one day and they received a Notice of Intended Prosecution, requesting the name of the person driving the vehicle at the indicated time. They weren't able to conclusively say, so they let it go to court. They told the magistrates that they didn't know who was driving at the time and explained their situation. They were allowed to get away with it so long as they make a record of who drives the car when in the future.
Can you believe that!?! They were extremely lucky, as usually the responsibility for the ticket lies with the registered keeper of the vehicle if the driver is not able to be identified.
Anyway, yes those box things that sit directly on the top of the traffic lights are not cameras - I think they're sensors so that the traffic light controller knows whether there are cars waiting at the lights or not. Red Light Cameras are like speed cameras but half the width, and often plain grey (i.e. not highlighted luminously) and sit next to the light, so that they capture a picture of the rear of your vehicle when you enter the junction after passing the light at red.