Skeleton Keys always had a bit of mystery to them as they have been used in the world of magic for ages. When doing spiritual work, many use keys on their altars to unlock the secrets to what they seek. 

The skeleton key is a strong symbol for breaking through barriers and creating a safe passage to your goal. In root work and conjure, keys have been placed in mojo bags, carried in pockets or worn around the neck on a string, just to keep it close to the body. Placing the key on your altar or hanging it in or above your doorway for protection was another common magical use.