TV Detective.

Daydreaming about an old hard-boiled fictional detective (like Sam Spade or ol' boy from Justified), but with a brain kinda more into problem solving (like Sherlock Holmes or Adrian Monk). Many years into his career he notices a pattern that he has only shot bad guys on Sundays. Never on any other day. And even then, only like 10 a year. And always 10. He's only shot 10 bad guys a year and only on Sundays for the last decade. Even though he's in his late 40's. He starts investigating himself and comes to realize that he is in a TV show.