First of all. If you go to Settings > Accounts > Sign in options, scroll down to mid page, under "Additional Settings", where it says "For improved security, only allow Windows Hello Sign-in for Microsoft accounts on this device (Recommended).

Next. Hold down windows and R keys. Type in netplwiz and hit enter key. When launched, check the box that requires username and password. Restart the computer and the second “ghost account” will be gone.