You could add an "old work" electrical box. You cut the round hole to size, insert box and twist the tabs to lock it in behind the drywall...
https://www.homedepot.com/p/Carlon-1-Gang-18-cu-in-PVC-Round-Old-Work-Electrical-Box-B618RR/100404072
__________________
---------------------------------------------------------------------------
"There is nothing to be learned from the second kick of a mule" - Mark Twain
|