Empty Pages is an anti-pattern in which people don't contribute to a page because it's empty. People are often reluctant to be the first to edit an empty page because they might be unsure what content should go on it. They may leave the page empty and assume that the person who created it will come back and start adding content at some point.
Look for pages that have been created but have no content, and haven't been updated in several days. A page hasn't necessarily fallen prey to the empty page anti-pattern if it's only been empty for a few minutes or several hours, so look for pages that look like they've been forgotten.
Talk to the person who first created the page, and see if s/he knows that it's sitting empty. If the person has forgotten about it, this will probably be enough to jog their memory and get them to add some content. You might suggest posting a scaffold at minimum, so that others know what to add to the page.
If you have a good idea what content should go on a page, you might just post a scaffold yourself to get things moving. Since it's a wiki, anyone can adjust the scaffold as needed.