Re: sims 3 supernatural zombies keep appearing everywhere

This is a bug. It happens if you save your game on a full moon.

All you can do is pack up your family (by saving to the library) and move them to a fresh savegame. There's no (mod-less) way to save the hood. On the new hood, don't save on full moons. Save right before and right when all Zombies are gone. Also save under a different name from time to time.