Ectoplasmic Feedback

Abjuration
Level: Sor/Wiz 2
Components: V,S
Casting Time: 1 Standard action
Range: Personal
Target: You
Duration: 1 minute/level (D)
Saving Throw: None
Spell Resistance: See text

A shimmering sheath of energy surrounds you, promising harm to incorporeal creatures that touch you.

Any creature that hits you with an incorporeal touch attack takes 1d6 points of force damage +1 point per caster level (maximum +10). If the attacker has spell resistance, it applies to this effect.

(SpC, p78)