Fan Balance Kit

If your overhead fan is swaying back and forth, you can easily balance it at home yourself. You can purchase a balancing kit, but it's just a clip and a small weight which you can easily print for yourself at home.

This model has a clip and a weight that are designed to weight ~3g when printed with PETG. PLA should work just fine too.

Then you can follow the instructions in a video like the one below to get your fan balanced.