Caching Service low on disk space

The Caching service is running low on disk space. The cache will not exceed the set 45 GB cache size or use the remaining 25 GB on the volume. Please increase the cache size or make more than 25 GB available on the volume.

I get this message occasionally from a MacPro running BigSur.
There is NO “Content Caching” pane in System Preferences – Sharing.
I periodically get these alerts and I want to fix the problem or turn off the alerts. How do I fix this?