After installing my Hampton Bay Fan, everything was normal. Several weeks later, the fan began to intermittently run backwards at 6 RPM (very slow) when both the fan motor switch and the light switch, (both are wall switches) ARE TURNED OFF!! It then stopped this behavior. Now, several months have passed and it's doing it again at 6 RPM.

This fan is in the same receptacle that two prior fans were connected to. The earlier fans never had this behavior in the nine years they were in service.

Otherwise, it works normally. Three speeds are still attained through operation of the pull chain and the original lamps are still installed after approximately one year of daily use.

Do I have a ghost? Termites? A squirrel in the canopy?
Ps. This fan is not a remote control fan.

Is there an air vent somewhere near the fan?

Is there an air vent somewhere near the fan?
No air vent present. Thanks for asking.
As of yet, I have not unmounted the fan to test for voltage. I'm hoping to get a few pointers of what to look for. With the light kit, blades, and canopy, it's a chore to take the fan down.

No air vent present. No Real Experts? Or it's a slow weekend...

Insult us, and expect answers? Ok.

Does the position of the reverse switch determine which direction it spins when it is running in "phantom mode"? If not, the problem is not electrical. I still suspect something along the lines of my first theory.

Insult us, and expect answers? Ok.

Does the position of the reverse switch determine which direction it spins when it is running in "phantom mode"? If not, the problem is not electrical. I still suspect something along the lines of my first theory.

A mild conniption would be a better definition. You’d think at my age, I would not expect instant results from a free advice provider, Yes?
(btw-Flipping the directional switch position had no effect and I should have included that as a symptom).
When I considered your latest advice of rechecking the area for vents, I realized the if there was source for a constant draft, it would need to come from the floor-up to cause the fan to revolve in the up direction.
The wife had repositioned her little powered air filter device! A constant baby’s breathe was reaching the tip of the blades. Enough to turn it at 6.2 RPM.
YOUR THEORY IS NOW FACT.:D

See, who's the real expert now? ;)

LOL!! Brilliant! I just had the same problem and checked out this page. My wife had a humidifier in the room blowing very little air directly up at the fan. I turned it off... and guess what?? It stopped. Well done "Ceilingfanrepair". Thank you. I'll call the Priest and have him head home. No exorcism needed.