I have a remote switch that manages both the light and fan. It has been acting as if it has a mind of its own. It comes on after it has been shut off. Replaced the battery in the wall switch and it still acts strange. Am I missing something? How do I fix it? It has worked well for years.

Until our resident ceiling fan expert gets back from his luxury vacation at his South Pacific private island, try checking out his note until he gets back:

https://www.askmehelpdesk.com/electrical-lighting/ceiling-fan-questions-out-town-again-1-week-47519.html

You need to change the frequency of the remote and fan. See:

http://www.ceiling-fans-n-more.com/ceiling-fan-remote-controls.php