I think there is a ghost in my cousins house, how do i find out the history of the home.?

You can check the history of the house and the land that it's on through the city or town records. Most of them go back hundreds of years. I don't think there is anything you can do about the agent that sold your cousin the house. You can again check the house history and see if any other family had the same problem. Tell the people, person in the house to go to the light, that they're dead. Maybe that will help them to cross over. Have you ever heard of Sylvia Browne? She has tons of books on this kind of thing. I hope this helps you.

The seller and real estate agent are obligated to tell you if there was a murder,suicide, or even haunting in the house. Houses like this are called stigmatized properties. If you wish to find out more talk to some of the neighbors and search through old newspaper clips about the area.

The easiest way to find out if there is to get a Medium to check the house. You can also search public records for any strange deaths. If perhaps you are being haunted by Indian Spirits, you may be built on an ancient buriel ground, in which case you have to call in a medicine man. See if your homeowners insurance covers spiritual exorcism's.

Legally... the seller and/or agent for the seller has to disclose any known paranormal activity.

So... if they knew about it, then yes... they have to tell you legally.