System notification being duplicated

  function Notifier() {
        switch (Url::getURL(2)) {
            case 'notifier':
                $render = 'dashboard/Notifier/notifier';
                $model = 'notifier/Notifier';
                break;
            case 'inbox':
                $render = 'dashboard/Notifier/inbox';
                $model = 'notifier/Inbox';
                break;
            default:
                break;
        }
        $this->_check_sub_menu_item($render, $model);
    }