2005 Daewoo Kalos Flashing lights appear to be draining the

My car hazzard lights will begin to flash. This can go on for several hours or overnight and is draining the battery.

The car has recently passed its MOT and service, but they cannot tell me why this is happening.

It is now happening on a daily basis and means that the car will not start unless I can keep some charge in the battery. As this often happens overnight now, its a daily occurance however no one seems to be able to tell me what the matter is or how to stop it.