Casablanca ceiling fan (Lanai model) with model W-52 remote controller, no light and no wall switch, gets turned on by a phantom signal at random speeds, day or night, cold or warm weather. Never turned off by same. Sometimes goes on multiple times in the middle of the night, and frequency of this happening seems to be increasing. Fan is about one year old.

What causes this? How could it be fixed? There does not appear to be access to dip switches or a means to change the wireless signal channel.

That's the thing about phantom signals, they are phantom and you'll pull your hair out trying to find where they are coming from. The dip switches are there, one set on the reciver which is most often inside the ceiling cap and the other set is inside the handheld remote under the battery cover. You just need to change one dip switch on each unit, they need to still match each other when you are done.

As Ballenger says, change the frequency of the receiver and remote:

Ceiling fan remote controls - help and FAQ- Ceiling Fans N More