Mazikim Erev Shabbos

 Sefer Chasidim (1170) Why do the spirits attack on Erev Shabbos? Because at that time there are no spirits in Gehinnom i.e. no spirits of the wicked which have died and become mazikim as all the descendants of Cain who upon death their souls became mazikim and have been given permission to cause harm to those that profane Shabbos or those who are depressed on Shabbos or even those who don’t feel pleasure on Shabbos…