A wraith trapped inside a magic item was released by the party last night, and the cleric turned it. Since the party was in the middle of the city of Scornubel, I had to think if it would go on a rampage of minion creation.
My thoughts:
1. Undead are not driven to reproduce their kind. That is reserved for living things. (Who seem to take great pleasure in initiating the process of reproduction...)
2. Undead *do* hate the living, and will attack them on sight; but will really only fight to the death if their lair is invaded.
So I decided that the wraith would wander about, draining life from the city folk, but not enough to slay them. But keeping an eye open for a lair. The party tracked it down (the wizard's raven familiar was keeping an eye on it- lucky thing it glowed), and it only slew a citizen to get a quick cohort to help in the fight.
What made it easy was that a wraith doesn't kill with one touch. Wights would be more problematic, but even then #1 would take priority.