Glitch,
I have been using a mix of wood chips and dry leaves this year and it seems to work beautifully. I also throw bags of leaves into the run/pen. The chickens love digging through them for weed seeds, bugs, etc. and seem to turn them much better than wood chips alone. I would be careful about using wet leaves because of mold problems and the possibility of diseases though. I cannot imagine why shredded paper wouldn't work.
I have been using a mix of wood chips and dry leaves this year and it seems to work beautifully. I also throw bags of leaves into the run/pen. The chickens love digging through them for weed seeds, bugs, etc. and seem to turn them much better than wood chips alone. I would be careful about using wet leaves because of mold problems and the possibility of diseases though. I cannot imagine why shredded paper wouldn't work.