Find the custom module responsible for a URL On a site I did not originally develop, I'm stuck having to fix display issues on an arbitrary page.

Is there a way to locate the custom built module responsible or the source of a given URL path?
You can use "hook_menu_alter" to list all routes and you can see the module via the module key.

function HOOK_menu_alter(&amp;$items) {
    if(isset($items['yoururlpattern'])){
        drupal_set_message($items['yoururlpattern']['module']);
    }
}