I would have the house checked for known toxins, including lead paint, lead pipes, radon, asbestos, and anything else known to cause problems.
As far as hants go, if you got them, the easiest thing in the world is to get them on their way by resolving their upset, fixation, or guilt, or whatever it is that hasn't been duly acknowledged. Ask them what they want. They'll probably tel you all about it. :D