Way To Search Content
Not all Drupal paths end with a content (or node) page. For example, the D7 core Contact module has the path /contact, but in order to "edit" it you need to change administration pages within the admin section (/admin...) or a theme template if you're wanting to change how the HTML is rendered.

The closest thing to what you're looking for is the menu_router (D7) or router (D8) database table. These DB tables contain static/dynamic paths (the path column) with additional metadata about what/how these paths rendered. They should help you discover what controls paths that aren't node or node alias paths.