Converting CE22 rotary switch

[Tpark]

I have a 2005 CE22 (with 57/08’s) that I am in the process of swapping out the rotary switch for a 3 way toggle and push/pull coil split. I ordered the McCarty drop in directly from PRS. They advised the multi conductor one. I installed the new one while following the McCarty wiring diagram. After completing I am getting terrible humming when touching anything on the guitar, regardless of which pickups are selected. From what I understand that is a grounding issue but not sure where I went wrong or how to fix. Appreciate any advice for troubleshooting!