A high-yield savings account (HYSA) is one of the easiest wins in personal finance, and I keep my whole ~$20,000 emergency fund in one.But sometimes it's the wrong tool for the moment. Sometimes it's the right tool, used badly.Here are some common situations when an HYSA is the wrong move -- and what to do if you're in one right now.1. You're carrying credit card debtIf you're carrying a credit card balance, pause everything else and attack the debt first. The interest you owe dwarfs the interest any saving ...