At one time it was believed that the skull was where the soul was carried in one’s body, that it was capable of possessing very powerful magical properties and thus was a hotbed of supernatural power. Light a skull-shaped candle on Halloween when you do spell work or circle ritual.
Necromancers use skull-shaped candles in their rituals to summon the dead. Anise essential oil is used to anoint candles used in spells to conjure spirits, while orris oil is a known protection against accidentally conjuring evil spirits. Ancient lore states that lavender oil can be used to give a witch the power to see ghosts.