There was someone who asked for help to find their lost snake a few weeks ago. Ill try to give you the recap. Sprinkle flower in the areas you suspect he might be, try placing a heat mat and a hide a different areas of the house, maybe a mouse (f/t otherwise you'd be looking for a lost mouse too) inside or around the hide, try looking at night, when they are most likely on the move, and finally, a few people said that even though ball's are not normally arborial, try looking up. I guess when they escape, they climb... I have only had 3 escapes in my days, all of which were my fault (left lids or racks open...), and luckily all snakes were recovered that morning... Good luck, and sorry if I mis-quoted someone,
~Johnny