Inflict Light Wounds

Necromancy
Level: Antipaladin 1, Artificer 1, Cleric/Oracle 1, Inquisitor 1, Shaman 1, Warlock 1
Components: V, S
Casting Time: 1 Standard Action
Range: touch
Target: creature touched
Duration: instantaneous
Saving Throw: Will half
Spell Resistance: yes

When laying your hand upon a creature, you channel negative energy that deals 1d8 points of damage + 1 point per Caster Level (maximum +5).

Since undead are powered by negative energy, this spell cures such a creature of a like amount of damage, rather than harming it.