It was believed that on that day, the souls of the dead returned to their homes, so people dressed in costumes and lit bonfires to ward off spirits. In this way, popular Halloween tropes such as witches, ghosts, and goblins became associated with the holiday. Encyclopædia Britannica, Inc.

The most popular event is the Official Salem Witches' Halloween Ball. Hundreds of costumed patrons flock to Salem as fires are burned on hilltops, while witches gather to cast spells for the new year and to honor the dead during Samhain (the ancient name for "Halloween").

Samhain (/ˈsɑːwɪn/ SAH-win, /ˈsaʊɪn/ SOW-in, Irish: [ˈsˠəunʲ], Scottish Gaelic: [ˈs̪ãũ.ɪɲ]) or Sauin ( Manx: [ˈsoːɪnʲ]) is a Gaelic festival on 1 November marking the end of the harvest season and beginning of winter or the "darker half" of the year.

Christian origins and historic customs. Halloween is thought to have influences from Christian beliefs and practices. The English word 'Halloween' comes from "All Hallows' Eve", being the evening before the Christian holy days of All Hallows' Day (All Saints' Day) on 1 November and All Souls' Day on 2 November.