Ron asks:
The Gemara says that we should assume the object in the hotel room was left by the last guest. Rashi explains that this is because a hotel guest will check his room before leaving. If the item is hidden in the wall how can future guests know to look for it. That we should assume that it came from the last guest
Ron, Efrat, Israel
The Kollel replies:
It is somewhat unusual for hotel guests to hide an item in the wall. However, if the last guest claims that he did hide it there, then we say to the earlier guests (who argue that the item hidden in the wall belongs to them): "If it is true that you hid the item in the wall, then why did you not check if it was still there before you left?" Therefore, we give it to the last guest.
Chag Kasher v'Same'ach,
Dovid Bloom