* The water source is uphill from where the wet spot is.
* If it is next to a wall, the water could be comming from the other side of the wall or uphill from that spot.
* I have had a pipe burst inside the wall due to the pipe comming through the slab and then the slab moveing up and down “Sanding” the pipe to the point where it burst.
* Take your shoes off and walk the area both near where the wet spot is and up and down the hall. The weight of your body squeezes the carpet and helps to show the moisture.
* The bathroom being the source is always a culprit. Check that your toilet is not leaking. It can leak, then the water follows the wall to where it exits and you detect it some way from the toilet.
* Good luck… Adios… Jasper…