Florida Law

When I've driven in Orlando, I often come to intersections where there's a sign stating that there's a red light camera. I've also noticed similar signs in other locations.

However, I've noticed a few places in Florida that the POI file claims have red light cameras that don't have a sign.

Does Florida law require that there be a sign for a red light camera, or are Orlando and some other communities actually being nice? (Or finding that signs work better than actual cameras, and are cheaper, too.)