Unless you have a PIN set on your account, anyone in that Home can ‘Switch User’ into your account.
If you have an own Plex server, you should never accept an invitation into someone else’s Home. Because by doing so, your own Home and its managed users are destroyed.
You can leave this home again by going here
https://app.plex.tv/desktop#!/settings/users-sharing
find your user name in the list, move your mouse over it,
move the mouse over the red X at the right-hand end of this line.
It should pop up a tooltip which says ‘Leave Home’.
