Alex McGee, a contributor of MetaFilter.com confirmed that the song was never used as a TV theme, claiming that it's his father who wrote the song. This song was written by Parker McGee.
England Dan & John Ford Coley's I'd Really Love to See You Tonight, however, has been featured in the television series, Cold Case (2004) in an episode called Daniella.
The duo also performed the song on the 1977 NBC drama series James at 15 in the episode "The Blowout".
The song was also heard in movies: Anchorman 2: The Legend Continues (2013) and in The Long Kiss Goodnight (1996).
England Dan & John Ford Coley charted six Top 40 pop singles, four of them Top Ten, in just four years. Their history goes back a decade prior to their first and biggest hit, "I'd Really Love to See You Tonight." The duo first met in high school in Dallas, TX, during the early '60s.
See England Dan & John Ford Coley's biography from Billboard.com.