When it is switched off, it blinks every few seconds. So, I guess
that there must be a problem with the switch If it is passing nothing
then it would seem impossible for the bulb to do anything. I did not
notice any problem with the previous incandescent bulb but I guess
that if the switch is leaking a tiny amount, the filament would glow
too little to be seen.


Is one of the switches illuminated? Those will pass enough current to slowly
charge up the filter capacitor in the fluorescent bulb and cause it to
blink.