One of my friends recently found some standing water in her basement. We still don't know how it got in this one little spot but it did make that room smell. Is there any way you have water standing? My friend found it by accident under a plastic basket, thankfully nothing was ruined. Anyways, look for water or, like above, rotting food. Look in small or hidden places. Hope this helped. I hope you find the stinker soon. ... View related article.