If you can see lights, could you see a laser dot for targeting? Would a firearm with an attached light help you? Given that your odds of shooting a person who doesn't need to be shot are a probably bit higher than a normally sighted person, have you considered some of the "less lethal" ammunition available for a 12 guage shotgun (rubber buckshot, rubber slugs, beanbags infused with pepper spray and/or marking agents).
If your floor creaks in different spots, maybe you could make a mental note of where the croaks are.
I like my Mossberg model 500, and it is available with a shorter barrel for indoor use.
Good luck to you!
Dead Bears, the only good kind.