Enervating Touch( Ghostwalk, p. 31)
Your touch can bestow negative levels upon creatures.
Corrupting Touch (Gh) , CHA 15, non-good alignment,
You can make a touch attack that bestows one negative level upon a creature. When you are manifested fully or attacking incorporeal opponents, you add your Strength modifier to attack rolls. When you are incorporeal, you add your Dexterity modifier to attack rolls. If the attack scores a critical hit, the number of negative levels is doubled (ghosts are not subject to critical hits). Bestowing negative levels does not heal you. Only one kind of damage or effect from the path of the corrupter applies from each attack.
Negative levels remain until 24 hours have passed or until removed with a spell such as restoration. At that time, he afflicted opponent must attempt a Fortitude save (DC 10 + 1/2 your HD + your Cha modifier). On a success, the negative level goes away with no harm to the creature. On a failure, the negative level goes away, but the creature's level is also reduced by one. A separate saving throw is required for each negative level.
You do not have to use this ability when you touch another creature, and creatures that touch you do not gain negative levels.
A ghost's touch attack normally deals no damage.