My mum is a hairdresser but she only does it on the side of her usual job (working with my dad) for friends and family etc. When I was younger, my mum would do the hair of this little old lady who lived alone. Sometimes my mum would drag me and my sisters to this old lady's house while she cut her hair because there was no one to look after us.
Eventually this old lady died in her sleep at her house. Of course the house was sold. A few months after this, my mum went to our neighbors Body Shop Party. After awhile, all the women got talking and my mum realized that one of the women there had actually moved into the old lady's house. This women (Julie) revealed to my mum that she thought the house was haunted and poltergeist activity like plates being thrown, radios turned on and off were happening. Also, Julie's son said that an old lady would stand at the end of his bed at night. My mum asked julie to describe the ghost and it was an exact description of the old lady! My mum then told Julie that an old lady she knew had lived and died there.
This julie was so scared she eventually got someone from the local church to come bless or what ever it is they do to the house! After that everything stopped!
Secondly, when a person dies in a place they are really attached to they sometimes stay. Most of the time they will go about their business and leave you alone. I would check and see if they maybe started some remodeling. That can cause a ghost to start becoming active. When you change the enviroment that they were used to they get upset and start causing a scene. I wouldn't worry much though. Good luck.