Worked at a retail store that sold big appliances. One day a couple walks in to buy a washer and dryer — paying in crisp $100 bills. My coworker, who’d been there for years and apparently considered himself part of the Secret Service, grabs one of those counterfeit detector pens to check the cash. He marks the first bill — it turns black. Then the next one — black again. Every. Single. Bill. Turns. Black. He freaks out, calls the police, and shuts down the register like he just busted a cartel.
Cops show up, look at the bills… and then at the “pen.”
Turns out the guy had been using a Sharpie.