Rest in Peace Spell (1) The Unknown Ghost
An ancient Greek method to lay a ghost to rest is especially beneficial if not only the identity but also the gender of the ghost is unknown.
Make distinctly male and female dolls from wood or true earthen clay (not synthetic substitutes as typically found among art supplies). It’s crucial to the success of this spell that the dolls be formed from biodegradable materials, so that they can decompose entirely without leaving traces.
Give the dolls a feast, a party in their honor. Have real food and drink, real fun.
When the party’s over, explain that their wanderings are over, too. Bury them in uncultivated land, where they are unlikely to be disturbed for a long time.
(from The Element Encyclopedia of 5,000 Spells by Judika Illes)