I installed a sku 27 power anode. In the instructions it highly recommended to use a power surge suppressor. I would try a power surge protector that has EMF/EMI filtering. The static you are hearing is EMI/EMF interference.
This can be from corrosion built up in your water tank. You can even try a basic snap on choke on the power cable.
I would also try a different radio to eliminate that it might be the radio. Also disconnect your wifi and microwave to see if the noise is eliminated.