In message , JM writes
Hi,

My security light in the back garden is a bit on the sensitive side - it
keeps coming on seemingly randomly throughout the evening and night.

John.

John,
if all obvious avenues that are being suggested fail then
consider local radio transmitters, taxis CB police etc. A lot of the
cheaper PIR's are RF (radio frequency) sensitive and can be triggered by
quite low amounts of power. There is no easy cure for this
unfortunately except maybe buying a better quality one with adequate
filtering. Hopefully it will be something like a cat or central heating
flue that is your problem.



--
Bill