Is it legal to sleep with a ball-peen hammer, for self-defense?
It is certainly legal to sleep with a ball-peen hammer, if that is your desire. A good solid kick to the person’s kneecap at just the right moment might be a better defense (try to break something), but if you are familiar with the old ball-peen, go for it. You may be wrong about the alarm situation. If you get some device (you can put it under the pillow with your ball-peen) that will make an extremely loud noise if triggered, that will scare away all but the most steely-nerved pervert. And once he’s gone, your safe. And set your cell phone to speed dial 9-1-1 (or your local equivalent) might give you peace of mind, also.