If you wander around your island at night occasionally you will run into Wisp, the secret resident ghost. One of the game characters informed me I was not to speak about him for fear it would ruin the island’s reputation.
It is not clear why Wisp is there. Legend has it that ghost hang around when they are not ready to cross over to the underworld. When you talk to him he gets startled, confusing you for another ghost who is going to hurt him. He breaks apart and instinctually 5 kindred spirits fly out of his ghostly body spreading out around the island.
It happens so fast it is as if 5 souls, were cloned and just shoved inside of him. He will then ask you to help him gather his spirit pieces and return them to him or he will be stuck like that forever, which may mean he has to actually cross over, no longer able to remain alive without the life of the spirits. If you agree to help, he will give you a reward, asking if you want something you do not have or something expensive. The concept gives me the sense that you are a real live supernatural bounty hunter working for the guild.
You catch the spirits with a net. Once you caught all five spirits return back to wisp who will reward you for your services and disappear into the night. Communicating with wisp is another way you gain wealth on the island.