Lately I have been seeing templates for a single file appear at the bottom of pages where I have other files in categories. The template for the single file is for one of the files that I have in the category on that page. (click this link for a screenshot.)
Have you checked your Settings > Display tab to make sure that you don’t have a check mark in the “Show attached files”? If it’s checked on files associated with a page will be displayed at the bottom of the page/post.