access panel

Hello,

I got a question if you don't mind, about the access panel which was installed in my closet. I have kept the panel out so I can check to see if it is leaking. All over my coats are little shredded pieces of wood, looks like from one of the studs above. Is this normal? I have not noticed any water.

Thank you.

http://www.fluidmaster.com/our-products/access-panels/14-x-14-access-panel.html

Mice? Is this into the attic? or a wet wall for plumbing? Could it just be that it was windy and some sawdust got blown around? Don't have a clear picture of what you are talking about.