Research a little before you try anything. It can save some grief.

Were this happening in my closet, my first thought would be to air the closet contents. Set up a line outside and hang everything after giving it a good shaking. You might even consider washing the washables. Dust the closet well, vacuum the interstices bugs might find to occupy.

Depending on what you want to repel, cedar oil, mint oil, garlic, hot pepper, citrus oil, they're all possible solutions. Not all of those are equally welcome in the closet, however. :)

SRS