What is the ruling on one who believes in the existence of ghosts of the dead? And does this constitute disbelief in and of itself?

What is said about the appearance of ghosts of the dead may be delusions, fear, or due to devils. It was narrated from the Prophet, peace and blessings be upon him, that he said: "There is no ghoul." And the ghoul is a type of Jinn that takes on different forms and misleads people. His saying "There is no ghoul" is not a denial of their existence, but rather a refutation of the Arabs' claim of their ability to transform and mislead. This is supported by another Hadith (definition): "When the ghouls appear, hasten to call the Adhan (definition)." Judging someone who believes in the existence of ghosts as a disbeliever is incorrect; because declaring someone a disbeliever is a serious matter that is only permissible with specific Sharia (definition) controls.