I have caught a wild mouse!! and i need help?

Well, your being mean and cruel to keep it. It would be much happier in the wild, idiot. There's a difference between mice you buy from the petstore and mice in the wild. Petstore mice don't know the wild so they can't miss it. Your unfortunate mouse will miss the wild if you still keep it and die a sad life of captivity forced upon him by an idiot like you.