If you're wondering if someone died in your house, it might be the result of healthy curiosity or a need for peace of mind. Every house has a history, some of which are longer and more complicated than others. As the present owner, you have every right in the world to inform yourself of your house's past. Luckily in today's society, there are numerous resources that should provide you with such information for minimal research time.
Contact your city or county's coroner's office. Explain that you're curious to know if someone died in your house and give them the address. They should be able to search their database via an address for place of death. They should have no problem doing this as the information stored at the coroner's office is public record.
Contact your city or county's house and property records department. While this department probably won't be able to tell you who died in your house, they should be able to give you a list of who lived there. Once you have this list, you can research each name individually.
Research your local newspaper's archives hunting for each name in the obituary section. You may be able to do this by doing a simple search on the Internet, or on the newspaper's website. Or you might have to call the newspaper directly and find out where they keep their archives, in physical storage or on disks. Arrange an appointment to go through them.
Take advantage of the Internet. Do multiple searches for each name on your list plus the city and state that you live in. You should be able to find out when and where they died or if they're still living.
You can also talk to the mail carrier of your house, or your neighbours. Your neighbours, of course, may not be able to provide you with information on the distant past of the house.