Spiritualism Gains in Popularity is a mythos card. It first appeared in the Miskatonic Horror expansion.
Mythos Type: Environment (Mystic)
Gate Opens: Devil Reef or The Witch House
Clue Appears At: Esoteric Order of Dagon or Black Cave
Mythos Ability: Investigators may not evade Undead monsters and receive -1 on Combat checks against Undead monsters.