Why do I get other users' notifications?

[anon(10385583)]

It started on Christmas 2017. I received a weird notification on my Motorola Atrix saying "Sign-in error for error410ytwhywhywhy@gmail.com" I tapped on it, and it blocked my screen with a prompt to enter my username and password. Restarting my phone unblocked it, but now I receive it every two minutes. Can someone help?

 

[Rukbat]

Try restarting in safe mode and see if it stops. If it does, some app you installed is trying to log into that account.