it sounds like you have a poltergeist M Sidhe and by the sounds of it a pretty tame and one that seems to be focused on you (there have been cases of the little buggers actually latching on to people rather then houses) and as Indigo Rain said poltergeists are simply the manifestations of a persons emotions so i would just calm down and go about your buisness however there is the chance that its behaviour could escalate (shown by flikering lights and what may sound like rats clawwing at something) if this does become the case i suggest getting four bags and filling them with various odds and ins such as crossroad dirt, silver flakes, white oak shaving, four leaf clovers and rose petals, and placing them within the walls of your house at the North, East, South and West corners, that ought to do the trick however consider it a last resort.