Saturday Night Live has made news for its fake news plenty of times over the years. On Dec. 12, 1981, however, it simply made fake news. The eighth episode of season seven, guest-hosted by former cast member Bill Murray, was filled with holiday cheer, including appearances by Santa Claus and a Christmas medley sung by the show’s cast alongside Yale a cappella group the Whiffenpoofs. But during the show-closing goodbye, Murray shared some decidedly serious news with the studio and viewing audience — that the USSR had invaded Poland, including the arrest of the Lech Walesa’s Polish pro-democracy…