Mystery part of charger?

The other day I got a liquid in charging port notification, so I shook my phone a bit and a small, metal, magnetic thing kind of appeared on my desk, I assume from my phone(iPhone 15) or my charger(regular apple USBC-USBC Charger). It’s like a rounded rectangle that has a white plastic covering one side, and the other is in two parts and is magnetic. No idea what it is from, and my charger and phone charging port both still work fine.