So they lit a bonfire and watched these evil spirits closely.
This is the origin of the saying that Halloween is full of witches and ghosts. Until now, some people in some isolated areas of Europe still believe this is true. Now all over Europe, people regard Halloween as a good opportunity to have fun, tell ghost stories and scare each other.
Legend has it that the souls of those who died that year will visit the world on Halloween. It is said that people should let visiting ghosts see the harvest and show rich enthusiasm to them. All the bonfires and lights, in order to scare away ghosts, also illuminate the route for ghosts and guide them back. The villagers dressed themselves as ghosts and spirits, wandering outside the village, guiding ghosts away to avoid evil spirits and disasters. So playing with ghosts on Halloween has been passed down to this day.