Unknown people using these devices
I’ve been alerted before by Apple support that a watch and AirTag have been linked to my account
AirTag
Question marked as
Inmeadietely change your Apple ID password.
After that: check on settings>your name on your iPhone to see if you see an unknown watch. Tap it, and delete it from your account.
After that, go to the find my app>objects, see if you see any unknown AirTag and delete it from your account.
See this link for further reference If you think your Apple ID has been compromised - Apple Support