A Gaekgwi is the wandering ghost of someone who died away from home. Having received no proper funeral or rites, it drifts without a place and is believed to bring illness and misfortune to the living.
Korean shamanism has a rite called "driving out the Gaekgwi," in which food is offered to placate and send it off, or it is threatened away. The dread comes from a death that never settled seeping into everyday life.