It is unwise to rent a room in your house without a rental agreement in place. You can pick one up at almost any Stationary/Business store such as Office Depot. There is almost nothing worse than having someone living in your very own house with you as you are going through a dispute. A rental contract can shorten the time you remain that way and can even scare off people with bad intentions. Besides, we don't want to have to see your smiling face on Judge Judy along with all the other people who had bad tenants in their homes!