Most of the species, deposit their eggs in decaying animal or plant material. They live in rotting stuff. Look for rotting food in your refrigerator or outside of refrigerator for old onions, potatoes, etc. Dispose of the source. Take drawers out and clean. They may be attracted to the light in the refrigerator.
Another source may be your sump pump area. Check for broken septic lines or cracked septic tanks. Check for plumbing leaks. You can also have the drains inspected for clogs or cleaning by a plumber if the above is not effective.

https://extension.umd.edu/resource/phorid-fly

Marian