Is there a ghost in my house?

Please don't answer if your just going to be sarcastic. I'm not a big believer in the paranormal myself, but this has me changing my mind. I'm 17 and my brother is 8, we've lived in house we live in now for 6 years. For the first months living there, it was fairly normal, had an eerie feeling, but it is an old house. The first year living there, we got the bathroom changed, we got a new shower, painted the walls. After that was done, I had a dream that I was under water in the bathtub a dark figure was over me and I heard the word "help" being screamed. My brother apparently had the same dream because he woke up crying and told my mom, and the next morning I told her the same thing. Ever since then, strange things started happening. Pictures would be knocked off shelves when you walk by them, blinds would be hit, you can hear footsteps, just strange random things. Last night I had another dream. I couldn't see anything in the dream but someone was talking to me, I can't remember much, but it was something like, "I'm here. I wait at the stairs." Or something like that. It was a female. Why am I having dreams like this? Should I get a recorder and record at the stairs or in the bathroom? What do you think?