100 series/hazard lights

Hi folks,
I have a problem with the hazard warning lights on my 100 series land cruiser.
4 weeks ago they started to flash by them selves.I took the car to a auto electrician who checked out the switch, after cleaning the switch and checking for any wear in it he said it was ok.after operating the switch the lights went off.
2 weeks later the same problem happen,.this time I disconnected the small plug on the back of the circuit board which is connected to the switch.This action stopped the lights flashing and the indicating lights were still operating.Now 2 weeks later the same problem is happening.
Hope some one can help.
Regards jaksun1