Filter or action hook to insert content on admin pages before tag

I am developing an administrator plugin and want to be able to write some HTML content just before the last body tag . This content will initially be hidden then displayed with javascript when a user clicks on a button.

Can anybody advise if there are any action or filter hooks that I can leverage to insert this? Remember this is for admin pages not theme pages.

You can use the admin_footer, admin_footer-(hookname) or admin_footer-(plugin_page) actions.