Robert Voets / AP

Kim Zimmer and Robert Newman starred as Reva and Josh on the popular daytime series, “Guiding Light.” After 72 years, the longest running series will air its final episode on Friday, Sept. 18. updated 9:26 p.m. ET Aug. 31, 2009

NEW YORK – Until not so long ago, Stage 42 at CBS’ Broadcast Center held a honeycomb of chambers where “Guiding Light” was shot.

Here stood a life-size dollhouse whose rooms (the Spaulding study; the Company restaurant; the Beacon hotel) fit together, snug as a Rubik’s Cube, providing multiple locations and ease of production.

Except that, by a Friday in early August, half of Stage 42 was a void. Roughly half of the set had already been dismantled. This was the last day shooting here at West 57^th Street. Then two final days on location in New Jersey. Then lights out for “Guiding Light.”

You don’t have to be a fan of the show, or of the soap opera genre it pioneered, to feel a sense of gravity at the demise of “Guiding Light.”

“It’s been reflecting American life back at America since before World War II,” said “Guiding Light” executive producer Ellen Wheeler.

“We are the history of so many people,” added veteran leading lady Tina Sloan. “They watched it for so long.”

But Friday, Sept. 18 (check local listings for time), they will watch its final hour, after 72 years and more than 15,700 weekdays on television and radio. It’s a run, an institution, that has never been matched and never will.

“I was just packing up my dressing room,” said a wistful Robert Newman, who began on the show 28 years ago, and, with only a couple of sabbaticals, has played colorful, oft-wed Josh Lewis ever since.

“I’ve got a lot of junk in there,” he mused.

As he spoke, a corridor outside the dressing rooms was jammed with racks of clothes and other costumes being put up for sale to the “Guiding Light” troupe.

“I took my nurse’s uniform,” said Tina Sloan, who began her run as nurturing Lillian Raines in 1983.

She made a joke about wearing the uniform at home and waiting for emergencies to handle, like she did at Cedars Hospital as Lillian.

“I’m mourning her,” Sloan said, turning serious. “They’re putting ‘Let’s Make a Deal’ in our place. All I can say is: BIG deal!”

Yes, a revival of the what’s-behind-the-curtain game show, this time hosted by Wayne Brady, will inherit the slot left by “Guiding Light” beginning Oct. 5. (Repeats of “The Price Is Right” will air in the interim.)

Glory days are over for soaps
It’s the latest chapter in the doomsday scenario that has plagued soaps for decades and has now claimed “Guiding Light.”

Used to be, at any given time there were a dozen-odd daytime dramas on the schedule. Soon there will be only seven. The oldest now becomes CBS’ “As the World Turns,” which began in 1956 (and, like “Light,” is owned by Procter & Gamble, whose line of household cleaning products inspired the “soap opera” term).

“Light” was created by soap matriarch Irna Phillips (who also masterminded “As the World Turns” and “Days of Our Lives,” now NBC’s lone daytime drama). It debuted on NBC radio in 1937 as a 15-minute serial, then came to CBS television on June 30, 1952. (Yet another Phillips creation, “The Brighter Day,” began on radio in 1948, then began its eight-year TV run in 1954.)

In 1968, “Guiding Light” expanded to 30 minutes and, in 1977, it became a full hour.

Those were the glory days of “Light” and daytime drama overall. Huge, faithful audiences flocked to their TVs at the appointed time each day, knowing each installment of their chosen soaps was a now-or-never proposition — thus not to be missed.

The genre was a cash cow. Time magazine in a 1976 cover story noted that the networks relied on profits from daytime to bail out their costly, deficit-financed prime-time shows.

Then, within a few years, soaps had peaked.

If the power of the soap has been its knack for reflecting changes in the culture, it painfully exhibited a range of cultural changes with its own steady loss of viewer support.

More women had jobs out of the home, away from TV sets, during daytime hours. Meanwhile, other TV genres were stealing soaps’ thunder as rival showcases for racy behavior and emerging social issues. How was even the scrappiest soap supposed to outpace the anything-goes world of daytime talk, reality shows or premium-cable dramas?

In the 1991-92 season, top-ranked soap “The Young and the Restless” was drawing 10.3 million viewers, with “Guiding Light” seen by 6.5 million.

By the 2006-2007 season, “Y&R” was still No. 1 — but with roughly half as many viewers. “GL,” in the cellar, had 2.75 million viewers.

Do-or-die time
But “Light” wasn’t going down without a fight, and a couple of years ago, it launched a do-or-die effort to save itself.

“We were given the directive to save money and be innovative,” Wheeler said. “We held onto the characters and the story and the history and the relationships. But we tried to change the style. It was time to deliver the stories in a more intimate way.”

By then, the narrative had gone through decades of evolution, leaving far behind the Chicago suburb of Five Points (where “Light” was first set) and its protagonist, the Rev. John Ruthledge, who placed a lamp in his window to welcome parishioners.

Now it takes place in the bucolic midwestern town of Springfield, and revolves around the sprawling, commingling Spaulding, Lewis and Cooper clans.

Their world was abruptly transformed in February 2008. Production changes for the show included ditching pedestal studio cameras and three-walled interior sets.

Hand-held video and realistic four-walled, ceilinged sets were suddenly the rule. And the whole production company began spending part of every week — a two-hour bus ride from West 57^thStreet — in leafy Peapack, New Jersey, which was cast in the role of the program’s Springfield hometown.