I haven't seen any but my sons claim that we have a serious zombie problem at our house. Not sure if that is better or worse than a ghost - yours seems rather friendly.
I'd believe them. Evidently, we also have a monster epidemic. My four year old son likes to inform us that he often sees a monster claw come out from under the house. When asked what color, he doesn't skip a beat, "Monster color!"
what fun. Things are so much better when accompanied by a child.