- light is randomly switched off
- off_value, on_value ( 0.0 - 1.0 ) 0 = dark 1 = full light
- off_delay_min, off_delay_max = min and max of time the light will spend in "off" state between flashes
- on_delay_min, on_delay_max = min and max of time the light will spend in "on" state 
- all delay values in seconds
- the actual delay time is randomly generated each time between the min and max values