Opportunity Knocks (1990)

Eddie and Lou are a couple of two-bit con men on the lam from a loan shark. They hide out in someone's house and they hear on the answering machine that (A) the owner of the house is out of the country for a month or two and (B) the housesitter supposed to watch the house for the absent owner won't be able to watch the house due to a new job in another part of the country. This provides for a pretty nifty arrangement for Eddie and Lou...until the relatives of the house owner drop by to visit. Eddie quickly adopts the guise of the person supposedly housesitting for the owner, and the shenanigans start from there.