The first World Series night game was Game 4 of the 1971 World Series, played on October 13, 1971, at Three Rivers Stadium in Pittsburgh.
By 1988, all World Series games were under the lights. 

This is my "Grail" ticket stub from the 1971 WS Game 7, Clemente hit a HR and led the Bucs to a 2-1 win over the heavily favored O's. Clemente was named the WS MVP.❤
The only ticket stub I'll ever need for my PC.