Can anyone tell me whats is happening?

i think my house is haunted. I have a 4 and a half month old little boy and me and my husband all living in a one bedroom flat. when we moved in and ripped up the old carpet that the council had down there was alot of dry blood under it. Musical toys that belong to the baby go off by themselves even when the batteries are removed. when my son goes to sleep teddies appear in the cot when neither of us put them there. i can hear someone calling my name and my husband can hear someone saying kill them all. the cooker door opens and closes itself slams open and closed. there are cold spots that you can put your hand in and out of and we have both felt something playing with our feet when we are in bed. shadows apear where we are not standing and we feel someone sitting on the bed alot when we are sitting there, even though the other one of us is in the living room. there are random bangings on ou walls and the hoover cord does itself up without us touching it. I have found a kitchen knife in the bedroom yesterday when neither one of us put it there, and my son keeps getting tucked back in the bed when neither of us have done and i know he cant because he is so young. When I asked the housing ociation what happened for there to be dry blood they have said they are not at liberty to disclose that information. I have typed my address into search engines and nothing has come up. I believe in ghosts and know this is flat is haunted, but can anyone tell me their opinion and what can be done, and how to find out what happened here before us. Soryy it's so long but it really freaks me out!!!