ExecPHP and includes

I’m trying to include a php file inside a post (there is just a div with several pictures inside the php file) It doesn’t seem to be working. execPHP is definitely running, I’ve tested it with an echo but nothing happens when I switch the echo for the include. Maybe a syntax error? Here is the code I’m using.

<?php include('wp-content/theme_name/electric-products.php'); ?>

I should also note there is no php error when I load up the page. Nothing happens at all. But the echo works fine…