Unexpected Find My sound played on iPhone without permission

If there is any reason to think that someone has learned your Apple ID password, you should change it.

If you think your Apple Account has been compromised - Apple Support

If someone with malicious intent knows your Apple ID and Apple ID password, they could do things a lot worse than just playing the "Find My" sound on your phone.

If you're part of an Apple Family Sharing group, and a member of your family has enabled Find My for their devices, you may be able to play a sound on their device using your own Apple device—but there are important conditions and limitations.

When it’s possible:

• Family Sharing is enabled and set up properly.
• The device you want to locate or play a sound on is shared through Family Sharing under the Find My feature.
• The family member has not restricted device location access through their privacy settings.
• You're using the Find My app on your Apple device (iPhone, iPad, or Mac) signed in with your Apple ID that is part of the family group.