A Family for Joe (1990)

The premise was that four cute upper-middle-class kids had been suddenly orphaned. About to be split up and sent to foster homes, they located a cranky old homeless man and offered him food, a home, and a decent life-style if he would live in their nice house and pose as their grandfather (this could only happen in a sitcom!). Of course he took his new responsibilities more seriously than they expected, and amid the quips, little lessons in life were learned by all around the sunny kitchen table. Roger was the helpful next-door neighbor, an air traffic controller turned homemaker.