Challenger 300 Captain reported squat switch weight-on-wheels malfunction resulted in numerous fault messages and diversion to nearby suitable airport.

Narrative

During our descent into ZZZ we began receiving a WOW FAIL CAS. Ran QRH and determined our increased landing distance and procedure. Message would come and go approximately 25 times. Then we began to have a cascade of faults. Stab trim Fault; engine faults on both motors; hydraulic pump faults. We elected to Request Priority Handing and land. We declared it as a major electrical fault. I was acting as PM. I went back to brief the passengers and the CH. PF Advised ATC and got us headed towards ZZZ1. I helped him load the procedure and brief. He did a great job; stayed high and fast in the event both motors rolled back. We knew we may not have brakes and had trucks standing by. Brakes worked normally but nose wheel steering did not. The CAS messages came and went constantly. Probably 40 messages in total. We think the aircraft couldn't figure out if it was airborne or on the ground. The back and forth was throwing codes for all systems. We landed and the fire trucks met us on the runway. Sat there for 20 minutes or so until a tug came and got us. Called ops; Chief Pilot and maintenance. Passengers were very friendly and happy. The kids enjoyed talking to the firefighter. They all thanked us while deplaning. Cause: I think possibly a bad PSEU (Proximity Electronics Unit). Maybe both WOW switches were bad.