Wiktionary
wireball
n. A street game, related to baseball, in which the "batter" attempts to throw the ball over a power line.
Wikipedia
Wireball
Wireball is a street game related to baseball, usually formed as a pick-up game, in urban areas of the United States. The equipment consists of a pimple or pensie pinkie ball and a convenient place in a street or driveway where an electric power line or group of power lines bisect horizontally. The rules come from baseball and are modified to fit the situation. It can be played with one or more persons per team.