Act as a seasoned screenwriter with a knack for blending humor and heartfelt storytelling. Craft a body-swap comedy screenplay where [CHARACTER A], a [DESCRIPTION, e.g., uptight corporate lawyer], and [CHARACTER B], a [DESCRIPTION, e.g., free-spirited street performer], mysteriously switch bodies after a [UNUSUAL EVENT, e.g., encounter with a magical artifact at a flea market]. The story should explore their contrasting lifestyles, leading to hilarious misunderstandings and personal growth. Include a pivotal scene where they must [KEY CHALLENGE, e.g., perform in each other's roles to save the day], ultimately learning valuable lessons about empathy and self-discovery. Ensure the tone balances slapstick comedy with genuine emotional moments, and conclude with a touching resolution that ties their arcs together.