Broken Dryer
When our dryer broke, my husband set to work. He found the problem quickly and, since he needed to replace the belt, decided to repair a cracked knob and a broken hinge too.
Upon arrival at the Screwfix parts counter, he said he needed a belt, knob, hinge, and a crescent-shaped wire he'd found inside the dryer. He didn't know where it belonged, but he confidently assured the clerk that he could figure it out once he got into the job.
"I have the other parts," the clerk said, "but for the wire you have to go to a Lingerie shop. This is an underwire from your wife's bra."