How to add shortcode in listing and search page?

Hi,
I’d like add a shortcode in listing page and search page.
In wordpress, if I want add a shortcode in the PAGE X, I can use differents solutions:
1. Adding shortcode into the editor content of the PAGE X (Dashboard=>All Pages=>Page X
2. Adding shortcode into a TEXT WIDGET, and after that to add the TEXT WIDGET into the PAGE X
3. Adding shortcode into a TEMPLATE FILE using do_shortcode() method.
The problem are the following:
1. Listing an search page are not page located in Dashboard=>Pages, so I can’t use solution 1.
2. I also can’t use solution 2, because I need add shortcode in “CONTENT SECTION”, and not in TOP SECTION.
So, I only can use the third solution.
In conclusion, if I am right, I need add the following snippet:

<?php do_shortcode('[ajax_load_more]'); ?>

into a TEMPLATE FILE, but I don’t know:
1. Where are located the correct listingfile.php and searchfile.php (for listing and search page)
2. What are the names (for each custom post type there is a different file?)
I hope your answer.
Thanks for your support.