Halloween movie from Oct. 2015

The way that IMDB works, movies each have their own message board, even if they're part of a movie series.

Television shows only have one message board for the entire series, even if there are multiple episodes and multiple seasons.

So there is one message board per TV Good Witch movie through 2014.

Beginning in 2015 Good Witch became a series and since the 2015 Good Witch special built on the same characters as the series it was added to IMDB as part of the TV series. It was added to Season 2 because it aired in the fall, and it was called Episode 0 because it was a special.

That's because the Halloween special was an episode, not a movie. Hallmark (and a lot of the smaller networks) do that a lot with shorter season series. When Calls the Heart had a New Years episode (of all things...?).