Add Template File to a Post Using Shortcode

// read file
function include_template_file ($template_path=null) {
	if($template_path == null)
		return '';
	ob_start();
    load_template( get_template_directory() .'/'. $template_path );
	$content = ob_get_contents();
	ob_end_clean();
	return $content;
}

// shortcode code
function include_template_shortcode($atts, $content=''){
	 extract( shortcode_atts( array(
	      'path' => null
     ), $atts ) );
	return include_template_file($path);
}

add_shortcode( 'include_template', 'include_template_shortcode' );

// Example:
// [include_template path='assets/my-file.php']