What would you say to your boss if he had a crazy idea but you think it stinks?

I would express my appreciation for their creativity and willingness to think outside the box, but then I would share my concerns about the idea. I might say something like, "I really admire your innovative approach, but I see some potential challenges with this concept that could impact our goals. Can we explore some alternative solutions together?" This way, I can provide constructive feedback while keeping the conversation collaborative.