Why Would the front passenger side floorboard be wet?

Sound,s like your heater box under dash is leaking,drain may be stopped up.There is a drain under car,passenger side little hose that drain,s the water out of the box,use air to blow it out,to clear it.

Or the heater core. Have you tried putting a rag on it to see if it's coolant or some other substance?

Three possible things are usually the blame on an SRX 1) Sunroof drain running through the roof A-post is leaking or dislodged (happens after a rain) 2) a/c drain hose is clogged/dislodged (happens in hot,dry weather) 3) Windshield seal has failed ( happens after a rain-push up on glass near A-post and see if you can see the glass move. This was the problem on my SRX and the windshield was laying loose in place, held only by the plastic trim on the outside. Windshield tech said it was a Cadillac thing (poor quality glue that doesn't last) and the windshield could come flying out during a hard stop or collision. Yikes!

roof drain failure. Ended up having to trade in at a loss, because dealer said they couldn't fix. 3 months later Cadillac had a recall for the repair.

I don't have a sunroof

I have a srx and it’s n the shop now for water being in the passenger floorboard but here is the kicker it’s just n the floor n front of the seat