Trick or Treat is a short (7 page ) Halloween themed adventure for 5E that can be found at the Dungeon Masters Guild. It's rather simple, but festive and fun. The party comes across a small town celebrating Reaping Day (a fall harvest and honouring the dead festival).The festival includes a haunted house, bugbear dunking game, and pumpkin carving contest. Unfortunately when a ritual is miscast by a clueless townsfolk member, people become their costumes.
I've read through the adventure and it seems like a fun romp. I love Halloween and like doing a Halloween game, so I'll be running this in my Storm King's Thunder campaign. Once the characters finish taking out the goblins and kobolds, they'll escort a rescued human home. The festival will be in full swing.
If you want something spoopy (and I mean spoopy, not spooky) and have two bucks to spare, you should pick this up.
I did notice a minor proofreading oversight. The Nightmare Before Christmas is attributed to "Time Burton."