I keep having the same dream of a haunted mansion with large rooms within a room. What does it mean?

Okay, so I have been dreaming of a large house I want to call it a mansion. The first part is a regular house where my family lives, my extended family and everyone stays in that part of the house. It is a regular house but we have to share rooms as there isn't space. However, I continue walking alone to explore the rest of the house. I see a huge empty room and I see stairs but I don't go up. When I'm in the room, there is another door and it is open. I can see that it leads me to a line of huge rooms. Some have a huge bathroom. But I don't want to sleep there.... I get chills.. it's creepy and haunted and it's strange that none of my family talks or acknowledges the extension of the house which is huge. In some dreams I see the outside and I see ghosts from the 1800s. People dressed the same way as back then and horses and I get chills. It's a huge front yard. But again, the family doesn't seem to acknowledge this either. This time though, I dreamed about the house again. I took my boyfriend to see it too. It was my graduation and my mom was there (I already graduated from college so don't know what type of graduation it was). So I took my boyfriend to the extended part of the house and I couldn't find the empty rooms. They were now turned into clothing stores with lots of people. It wasn't scary or haunted anymore. But I continued to search for the haunted large empty rooms and I was given instructions by a boy who was shopping as to where they were. I found them, they were empty and creepy so I ran. I ran away back to where the stores where. It was too scary. I woke up to thunder. lol anyone had this dream before? what does it mean?