Spirits are naturally drawn towards messy place! Plus if it is not visited regularly there is a chance of spirits inhibiting there since they don't like being disturbed.. My suggestion is that search the background of the house. If there is some strange case involved its time to tidy up the place. If nothing comes up then you have nothing to worry about. If spirits were to come to all dusty or messy place, all teenager's room would be infiltrated with spirits. LOL. If you are being troubled with Paranormal activities before then its best not to take any chance. Tidy up the place. Get an exorcism performed if absolutely necessary. Otherwise you have nothing to worry about. Have a good day !