Clearwall

You touch a door, wall, or similar surface and render a 10-foot square of it invisible. The material retains all of its other properties. Creatures on the both sides of the material can see through it. The maximum depth of the material you can turn invisible is 2 feet. Rendering a surface invisible reveals any objects within it. Thus, you could turn a door invisible to reveal the trap and locking mechanism inside it or a section of wall to reveal the secret compartment beyond it.

This spell does not affect constructs or creatures pretending to be a door, such as a mimic, nor does it affect magically enchanted materials or spell effects like wall of stone.

*From Kobold Press: The Wizard's Playbook