How to include non-users in wp-admin redirect?

You can do something like this to redirect everyone that enter to the wp-login.php

Notice that its redirect only when the request is GET so you could still can enter if you post to there. its in the case that you use this wp-login.php with your custom login page.

function login_page_redirect() {
    $redirect_to = "http://google.com"; // url where to redirect
    $page = strtok(basename($_SERVER['REQUEST_URI']), "?");
    if( $page == "wp-login.php" && $_SERVER['REQUEST_METHOD'] == 'GET') {
        wp_redirect($redirect_to);
        exit;
    }
}
add_action('init','login_page_redirect');