Search all custom post types at at once

Hi

Is it possible to search for all custom post types at once, and remove the Post Type selector from the search?

eg a custom post type ‘online_business’ would show up alongside ‘places’.

From what I can find this isn’t possible, but some of our listings don’t have an address and creating a CPT is apparently the only way to add them to the system – but we still want them to show up alongside other stores as normal in the search, not be split up like this.

Thanks hope you can help!