The ghost and us (2009)

Laura's thrilled with her new boyfriend, not so thrilled that his house is haunted by the ghost of his dead wife. But when she finally decides enough is enough, it turns out playing ghost buster is harder than she thought. Over a night that includes microwave s'mores and a shoot-out with holy water, Laura has to ask herself--how do you exorcise a ghost whose name is on the lease?