Thanks for your help. I tried replacing the foot switch but that didn’t fix it.

I was eventually able to fix the issue. The pedal had plastic jacks and needed a better connection to ground. I soldered a wire from the first prong on the out jack to the metal ring between the foot switch and the pedal case. I didn’t solder the wire to the ring but rather wrapped some of the wire around it before screwing the switch on.

Has not had any issues with buzz since.