Maybe it’s the advent of sweeps month, but there are a lot of intriguing guest spots this week. Marion Ross, Mrs. Cunningham on Happy Days, and Wendy O. Williams, the punky former lead singer for the Plasmatics (how often do you see those names together?), appear on Monday’s MacGyver (ABC, Nov. 5, 8 P.M. ET). That same night (8:30 P.M. ET), Vice President Dan Quayle turns up on CBS’s Major Dad. The most unlikely cameo comes on a rerun. Opie (Ron Howard, who went on to play Marion Ross’s son on Happy Days) finds a baby on The Andy Griffith Show (TBS, Sat., Nov. 3, 5:05 P.M. ET). The boyfriend of the girl who abandons her child in Mayberry is played by that manic antihayseed Jack Nicholson.