Wojo took a call from a woman who wanted to report a missing family but he told her there was nothing that they could do.
Turns out she was reporting 'The Waltons' as missing.
Harris threw in a sarcastic comment that the mother was a nurse now.
As for Michael Learned, who played Olivia, she actually was a nurse... on TV. In 1981 she starred as a widowed nurse who got back into the routine of work. And the show used her job description as its generic title.
Maybe it was in "Endless Tomorrows", the fictional soap opera which was part of a subplot in an earlier episode of 'Barney Miller'.