"Apple Store" in known Wi-Fi networks

The Apple Store network is exactly what it says; this is the guest network that you will encounter in any of Apple’s physical bricks-and-mortar stores. All your WiFi networks are stored in your Keychain.

Don’t forget, all of your devices that are signed-in to iCloud with the same AppleID - and have Keychain in iCloud enabled - share their saved credentials. As such, if you have in the past visited an Apple Store and used the free in-store WiFi network, this will be saved in your Keychain and shared across all your devices.

The WiFi networks are stored in your Keychain. Have you ever visited an Apple Store with another Apple device that you already own?

If so - and you used the in-store WiFi, the network will have been added to your iCloud Keychain - and for this reason is visible to you.