I know it's unlikely to be you, but if you know anyone concerned about someone who had access to their phone tracking them (or other malfeasence), Apple published a "Personal Safety User Guide":

https://help.apple.com/pdf/personal-safety/en_US/personal-sa...

(also a web version: https://support.apple.com/guide/personal-safety/welcome/web )

(and yes, it covers AirTags).