Displaying External Data – Not Posts

You can hook the content of any post and request data you want through WordPress HTTP API.
Like this:

add_filter('the_content', 'my_content_178750', 1, 99);

function my_content_178750($content) {
    return wp_remote_retrieve_body(wp_remote_get('http://example.com'));
}

Also there is possibility to check path you’re on and decide what you want to get depending on that.