Out cold (1989)

Sunny is married to the butcher, Ernie, and their marriage is about to end as both of them have affairs. Thus Sunny hires Lester Atlas as private investigator in order to collect proof for the divorce. One evening drunken Ernie and his partner Dave have a fight in the butcher shop with Ernie getting knocked out in the fridge where he dies during the night. But it was not Dave's fault but intentional murder by Sunny. Only Lester has proof so Sunny kills him, too. Thus she only has to kill Dave to get rid of all witnesses, but he can free himself out of the fridge and wants to take revenge.