Place mashed potatoes in a large bowl; let stand at room temperature for 30 minutes. Stir in the egg, cheese, onions and bacon bits. Shape into 1-in. balls; roll in bread crumbs. Let stand for 15 minutes.
In an electric skillet, heat 1 in. of oil to 375°. Fry potato balls, a few at a time, for 2-1/2 to 3 minutes or until golden brown. Remove with a slotted spoon to paper towels to drain.