You notice incorporeal creatures, even those lurking in walls.

Prerequisite(s): Psychic Sensitivity or the ability to cast psychic spells, Spirit Sense.

Benefit(s): You can sense the presence and movement of incorporeal creatures though solid walls, as long as that incorporeal creature is adjacent to you. When you sense a creature in this way, you can attempt a Knowledge (religion) check to identify the creature and its special powers or vulnerabilities, with a –5 penalty. When you sense an incorporeal creature with this ability and use a readied action to attack it when it attacks from inside the wall, it doesn’t gain cover against your attack.

Normal: Incorporeal creatures are silent unless they choose to make a sound and are thus almost impossible to detect when inside a solid wall. When readying to attack an incorporeal creature in a solid wall, it gains cover against your attack.