How do I get the alarm to stop

What is your question?

Two days after I purchased the car the alarm starting going off for no reason. In November the alarm was dismantled and is in my back seat. The alarm still goes off and the hazard lights also go off when the alarm goes off

What makes this problem better or worse?

Nothing

How long has your 2006 Mazda 3 had this problem?

About 3 months