Each evening before he goes to bed, I Wayan Gama completes a simple ritual to protect his family as they sleep. The artist walks through the tidy grounds of his family’s compound in Keliki, a jungle-draped village in Bali, Indonesia, and locks the metal doors of the stone gateway that is the sole entrance and exit. He does this not to deter criminals, but to block something less visible but just as potentially harmful. This Hindu-majority island in the world’s most populous Muslim nation is inhabited, it is said, by…