Use cedar blocks to deter moths in wardrobes and stashed items. 

You can buy cedar balls in supermarkets and hardware stores (expensive) or you can cruise around the local cabinetmakers, classy fence makers and woodworkers and pick up their cedar scraps.  Be sure that IS what you are getting.

I saved all the sawn-off pieces from our cedar fence and they have been put to use in the boxes where I store the Christmas decos from year to year.  I had enough to give some to a neighbour! Plus some I sanded with the Dremel, screwed small eyelets in and hung on clotheshangers in the wardrobe.  No more moth holes in my (eBay purchased) cashmere sweaters!