Traditional Chinese folk superstition sees some families seek help from “egg-standing exorcists” who try to balance raw eggs on mirrors or kitchen knives to detect spirit possession. If the egg manages to stand upright, legend has it that a wandering spirit has taken over the person’s body. Traditionally, a superstition known as Cai Zhuang Ke, which is often referred to as “spirit possession”, is used to determine whether a sudden illness or extreme lethargy is caused by a wandering spirit or...