Factory alarm going crazy

Ok this is my first post so go easy on me. I have a 2002 grand caravan 3.3 and the alarm will go off randomly( horn sounds back hatch opens and closes by itself sliding door also opens and closes). So I am clueless as to what is causing this. Alarm does not have to be activated to have this happen. It all happens at random. Any suggestiOns will be appreciated.