The word “ghost” simply means spirit.
As Catholics we believe in the existence of spirits: angels & demons, our own souls when they leave our body for hell or heaven or heaven through purgatory, and we worship a Spirit: God is spirit.
Many may be aware that the third Person of our Triune God, the Holy Spirit, is sometimes referred to as “Holy Ghost” in older English for this very reason.
So when people ask me if i believe in ghosts, i say “yes”. Do i believe in hauntings? also ‘yes”. People receive visitors from the eternal realm all the time. Just make sure you’re being visited by a good ghost and not a bad ghost. If it’s a bad kind of haunting, ask your priest about an exorcism.
So while you enjoy your fun spooks, tonight don’t forget about real spooks and don’t forget to pray for the Holy Souls in Purgatory this Halloween. (It’s my theory this was the origin of the ghost, skeleton, and mummy costumes: reminders to pray for the dead.)