Guiding Light shuts down after 72-year-run.

The soap standby began as a 15 minute radio serial on NBC in 1937 and made the cross over to the cathode ray tube when it debuted on CBS TV in 1952.

Like most day timers Guiding Light suffered from declining ratings in the era of "reality" TV, infomercials and news, and CBS is looking to save some bucks by not having to pay cast members and feed them despite being cited by the Guinness Book of World Records as the longest-running television drama – EVER.

"No show in daytime or prime time, or anytime, has touched so many millions of viewers across so many years as ‘Guiding Light,’"  Barbara Bloom, senior VP daytime programming @ CBS said.

Successful alumni from GL include Hayden Panettiere, Kevin Bacon, Taye Diggs James Earl Jones and Calista Flockhart among others.

FYI: The show’s title refers to a lamp once lit in the study of Reverend Dr. John Ruthledge, a major character when Guiding Light debuted in 1937, that folks could see as a sign for them to find help when needed.

Lights out.