Hi- MNSSHP stands for Mickey's Not So Scary Halloween Party (which I have never been to) which is held at the MK on a bunch of evenings in Oct. after the park closes. There is a separate admission charge just like Mickey's very Merrry Christmas Party. We are going at the end of Oct., so we will probably attend. The only thing I'm concerned about is the crowds. People who have attended rave about it though- there are candy stations for trick or treating,special parade, decorations, certain rides are open, special photo included, etc.
Dina