WordPress at a glance
action is not described

admin_footer-widgets.php action-hook . WP 1.0

This action is documented in wp-admin/admin-footer.php

Usage

add_action( 'admin_footer-widgets.php', 'action_function_name_6936' );
function action_function_name_6936(){
	// action...
}

Where the hook is called

WP_Customize_Widgets::print_footer_scripts()
wp-includes/class-wp-customize-widgets.php 841
do_action( 'admin_footer-widgets.php' );

Where the hook is used (in WP core)

wp-includes/widgets/class-wp-widget-media.php 114
add_action( 'admin_footer-widgets.php', array( $this, 'render_control_template_scripts' ) );
wp-includes/widgets/class-wp-widget-text.php 68
add_action( 'admin_footer-widgets.php', array( 'WP_Widget_Text', 'render_control_template_scripts' ) );
wp-includes/widgets/class-wp-widget-custom-html.php 77
add_action( 'admin_footer-widgets.php', array( 'WP_Widget_Custom_HTML', 'render_control_template_scripts' ) );