Your AirPods will not play a sound while they're in the case, so if you lose the AirPods and the AirPods Case somewhere in the house, you're out of luck. There's also no way to track the AirPods case because a Bluetooth connection is needed for Find My AirPods, so there is no option for locating a lost case.
Can stolen AirPods case be used?
You might think a thief can't use your AirPods if you still have the charging case. So, if a thief stole your AirPods, they can still connect them to another iPhone using a different AirPod charging case.
What do I do if I lost my AirPod case?
So if (and when) you lose your AirPod Charging Case, Apple replaces your lost item for a fee of $59-99 USD. That AirPod case replacement is either new or equivalent to new in both performance and reliability. If you live near an Apple Store, call the Store to see if they offer AirPods case replacements.
Can you swap AirPods case?
If your AirPods or Charging Case get damaged accidentally, you can replace the damaged item for an out-of-warranty fee. If you lose an AirPod or your Charging Case, we can replace your lost item for a fee.