Cap off a 18 to 24 inch long piece of 4 inch PVC pipe with a double layer of screen. Fold the screen up and over the end of the pipe and fasten it on with a hose clamp. Wrap a glob of peanut butter in a piece of cheese cloth or pantyhose and place it in the PVC pipe. In an upright position, fasten the pipe holding the bait to a tree or a post screen end down about 2 inches above the ground near the problem area.
The chipmunk will smell the peanut butter, climb the post/tree and fall in to the pipe trying to get at it. The chipmunk will not be able to climb back out. Relocate or dispose of the chipmunk as you see fit.
Keep your fork