Perhaps the most famous worked example is Have you stopped beating your wife?, an instance of a rhetorical device called begging the question; strictly speaking, this is Dark Arts, but since you are assumedly willing to immediately take a step back and change your mind about the assumption (as in, 'Oh, you're single' or 'Oh, you've never beaten her' or 'Oh, you only beat other people's wives') it should not be that bad.