apparition,
spirit, specter, phantom, ghoul, vision
flicker,
trace, impression, flash, glimmer, suggestion
phantasm,
spirit, apparition, specter, phantom, shade (literary), spook (informal)
phantom,
apparition, spirit, specter, phantasm, spook (informal), shade (literary)
poltergeist,
spirit, manifestation, apparition, specter, phantom, presence
presence,
apparition, spirit, ghoul, manifestation, specter, phantom, phantasm
shadow,
specter, spirit, wraith, apparition, phantom
specter,
apparition, phantom, spirit, spook, wraith, vision
spirit,
ghoul, soul, phantom, apparition, specter, spook
spook,
wraith, phantom, apparition, spirit, vision
wraith,
phantom, apparition, spirit, specter, shade (literary)