Not everything to do with the law has to be serious. In fact, there are some interesting laws that you may violate that are so unusual that they're laughable. Realistically, since the laws are on the books, you could end up charged with a federal crime if you committed them, but the reality is that no one would be likely to prosecute you.
For example, did you know that it's a violation to wear a post officer's uniform if you're not one? This applies to every day of the year and every event, even Halloween. Impersonating a government agent, which also includes a postal worker, is against the law. You probably won't face charges if you do this when you're at a costume party, but impersonating a post officer in other situations could get you in trouble.
Another law that is often broken is damaging federal notes, like the dollar bill. Ripping it in half, writing on it or changing it in other ways can result in charges, though they're highly unlikely.
Funnily enough, many of these seemingly harmless acts can get you into deep trouble under the right circumstances. For example, damaging a mailbox is a federal crime, and if caught, you could face serious penalties for doing so. Should you face more than the cost of a new mailbox? That's something that your attorney would help you with if someone decided to press charges.
White collar crimes and other federal crimes come in many shapes and sizes, so make sure you reach out if you're accused of an unusual crime.