Is there anywhere near the wet area that you can get inside the wall to see if its wet and if its running down the wall?
I had wet carpet, very wet and no sign of a leak anywhere. I opened up a cabinet near the floor and it was wet inside ( under the entertinment center ) worked my way up removing wallboard ( all hidden in cabinets ) worked my way all the way to the ceiling and it was a loose pex fitting. I tightened it up and leak is gone.
Good luck
Jeff,Julie,Amber,Brandon,and Casey and Winston ( our 5 year old Golden ) and Bruno the Pug. We now have an English Cream, white Golden Retriever as well.
2015 Keystone Montana Mountaineer 356TBF
2005 Chevy duramax dually