In an interesting move, you can apparently purchase tickets for the 2019 MNSSHP event starting...now!
https://disneyworld.disney.go.com/events/mickeys-not-so-scary-halloween-party/purchase/
A few interesting things I noted:
- party starts Aug 16
- 3 parties a week in September and 4 parties a week in October!
- Halloween night is the most expensive at $135 ($130 if purchased in advance)
I'm absorbing..... 
This blows my mind. Why not go ahead and put the Christmas ones up for sale too!!!!
"I do not like the cone of shame."
"I want adventure in the great wide somewhere. I want it more than I can tell."
"It seems to me that we have a lot of story yet to tell."
A few interesting things I noted:
- party starts Aug 16
I'm sorry - that is just WAY too early to celebrate Halloween. I love MNSSHP as much as the next guy, and I realize they are trying to pack in as many folks as possible (especially at the high prices) but I have to draw the line at Halloween in mid-August.
Totally agree! And the weather is so sucky in August I can't imagine costuming up. But Halloween decorations in August.... 
