I installed a Hampton Bay Outdoor Wall-mounted lamp with motion-sensor. The installation comes with a 100 watt incandescent lamp. The fixture works as described. I replaced the incandescent lamp with a 23 watt spiral fluorescent lamp (100 watt incand. eq.). It works as described except when it is off, the lamp flickers; comes on as necessary, but flickers when no motion detected.

Do I just have a bad fluorescent lamp?

Thanks.

This is normal. As it is a function of how fluorescent lamps work and the fact that it uses ballasts.

Here is some more information