Voodoo was a mystical practice that was believed to be able to enable the user to harm people or things by harming representations of them. This was believed in several cultures on Earth, and was also mastered by the Pain Casters on Vulcan. Count Dressler mastered the practice and began using it to attack Earth in 2266 until he was stopped by the crew of the USS Enterprise. (TOS comic: "The Voodoo Planet")
Benjamin Sisko once asked Kira Nerys if she knew if the Cardassians practiced anything like voodoo. (DS9 novel: Station Rage)
When Gaila asked James T. Kirk how he knew how to pleasure her so well, he replied that it was voodoo. He claimed that it was "ancient secret Terran technology." (TOS novelization: Star Trek)