dusty wrote:

You are correct when speaking of expensive motion detectors like you find
in commercial environments however some of the cheap ones from the BORG
can be all over the place on what they detect, I once had one pick up the
change in light from a defective street light. Every time the street light
went off it would turn on the driveway light.

But I'm NOT necessarily speaking of "expensive" motion detectors. Those
used in my alarm system cost something like $35 wholesale and include
both coded, multi-frequency capable radio transmitters and relays if I
want to run them wired.

That "defective" street light was not, I'll bet, a fluorescent tube
device and when it turned OFF or ON (not flickered at 60hz) it created a
change in temperature in that zone, hence your motion sensor on the
driveway light picked it up. There is generally a sensitivity
adjustment on your motion sensor as well as directional "tweaking" that
likely could have solved your problem.