It just so happens that Halloween is based on the ancient feast called All Hallows Eve. It's the one night of the year where the spirits of the dead can return to Earth.
12 seconds sound clip from the Hocus Pocus movie soundboard.
You can hear this line at 00:13:19 in the Blu-ray version of the movie.
Quote context
[...]
- Ah-ha! We seem to have a skeptic in our midst.
- Would you care to share your California, laid-back, tie-dyed, point of view?
- Fine. But everyone here knows that Halloween was invented by the candy companies. It's a conspiracy.
- Well, in case Jimi Hendrix shows up tonight, here's my number.
[...]