A robot to navigate crawlspaces and show video.
A boon to pest control or plumbing estimators. Rather than dry suiting and taking pictures (homeowners usually have at least three estimates), one could show live video of pipe leaks, festerring sewage, carpenter ants, termites, racoons or mice nesting.
Perhaps the robot could carry a stun gun to drive out raccons. It has to be able to navigate the "wild" underside of homes or buildings and be waterproof. It could have an articulated arm to mount the camera and poke holes to search for termites.