I have a remote control fan and light combination that has worked perfectly. The unit is wired to a wall switch. Now when I turn on the wall switch the fan comes on as well as the light. When I use the remote to try to turn the fan off I can hear the motor pause momentarily then continue to run.
How can I re-set this so fan comes on only when I turn it on?
Is it possible to get interfearence from cell phone RF?

That is a very unusual problem. I only have suggestions to try. No guarantees.

With interference, it usually has to be present all the time. The frequencies used in remotes should be far away from cellular. A new neighbor's toy might cause problems, but I highly doubt it.

For a first try, what I would do is reseat the programming switches. Just move them from their cuurent position and back again.

I'd also make sure the batteries are fresh.

If that didn't soldve the problem, I would try other frequencies.

Usually there are DIP switches in the canopy and remote to change the frequency.

Sounds like something has shorted in the receiver.

Is it a normal on/off wall switch?

I would also try turning off breaker to that room for a minute, may have gotten confused.

Sounds like something has shorted in the receiver.

Is it a normal on/off wall switch?

Yes it is a normal wall switch and prior to this it all worked as expected.
This happened in another room on a identical fan and the problem went away after a few days.

If it doesn't go away, you may have to replace the receiver.