When "The New Neighbors Meet the Addams Family," the pretty blonde wife takes one look at the mansion next door and comments to her husband, "Horrible house next door! Do you suppose anybody lives in it?"

"Honey, I didn't even know that house was there," her husband responds. "As I remember it, the renting agent had the shudders closed on this side."

This Addams Family episode basically wrote itself, by casting a quintessential happy American couple as Morticia and Gomez’s new neighbors.

Playing the husband was Peter Brooks and playing the wife was Cynthia Pepper.

Both Brooks and Pepper had previously played recurring roles on the wholesome sitcom My Three Sons, with Brooks playing Robbie Douglas’ friend Hank Ferguson and Pepper playing Mike Douglas’ first steady girlfriend Jean Pearson.

For Pepper, playing Mike’s sweetheart briefly turned her into America’s sweetheart before she had gotten hardly any acting experience.

"I guess I was exactly what they were looking for on My Three Sons, so they didn't hold my lack of experience against me when they hired me," Pepper told the Argus-Leader in 1961. "I was the only girl to have a running part on the series. It was a good show and I'm grateful to it for launching me in television."

See More

Which Addams Family member said these hilarious lines?

Pepper had a unique beauty that soon attracted more TV offers. One writer for The Hartford Courant in 1962 captured why she swiftly caught casting directors' eyes: "Her particular brand of youthful loveliness seems to deny any taint of artificiality."

She was born to the comedian Jack Pepper, of the famous vaudeville comedy duo Salt and Pepper, and a dancer mother, but she said she didn’t start acting until her teens because her parents didn’t want to push her into show business, even if she did grow up "living out of a trunk."

"I have led a very normal life, not much different from any other young girl until I was graduated from Hollywood High School and really got my acting career started," Pepper said.

After My Three Sons, Pepper was picked to star in a TV series of her own. Margie was about a teen girl living through the tumultuous changes of the roaring '20s.

Again, it seemed that Pepper just had that star quality producers were looking for. Even though she was about four years older than the part she was playing. The producers didn’t even notice!

"We interviewed more than 100 young girls for the role," Screenwriter Hal Goodman told The Ottawa Journal in 1962. "We screen-tested 17. When we talked to Cynthia, we knew she was it. When we tested her, we were positive. She was exactly what we were looking for, with more sparkle than we had hoped to find."

But Pepper knew there was a problem. Her age.

By this point in her career, she was 20 and no longer a teen.

However, she looked so young, Pepper said everybody just assumed she was a teen, and after she was cast, she remembered feeling terrified to have to break the news she was older than she appeared.

"They had just given up trying to find a 16-year-old actress and were looking for an older girl who could play and look the part," Pepper told The Courant. "When they saw me on My Three Sons, they auditioned me and said they were happy they found a teenager to play the teenager. I was scared to death to tell them I was 20 and no longer a teenager, but I swallowed my breath and did. I don't think I was ever so happy as when they told me that it was all right, because I was just right for the part anyway."

"Just right" were two words Pepper got used to hearing in the Sixties.

"I guess I have that youthful, innocent look," Pepper said.

But then Margie was canceled after only one season. She continued taking roles in movies and TV, most notably starring as Elvis' love interest in the 1964 movie Kissin' Cousins.

That same year, she appeared on The Addams Family and returned to My Three Sons to reprise her role as Mike's now ex-girlfriend. This episode, called "Goodbye Again," Pepper has posted a clip on her Facebook dubbing it her favorite episode.

She continued taking roles on TV through 1970, but then she only appeared a few more times in her career, retiring from acting. It was as if the older she got, the fewer roles seemed to be "just right."

Since then, her fans have found her at Elvis fan events and conventions, where she’s cherished for her personal appearances.

At the height of her fame, she joked that staying young was the only way she'd keep succeeding. That ended up being rather prescient, unfortunately.

"Stay young," Pepper said. "That’s the way to make my career last. Do you know I’ve only played my own age once. That was way back when I was 19."

Last year, Pepper turned 80 and more than 100 of her devoted fans swarmed her Facebook to wish her well, fondly remembering that sparkle after all these years. She responded to let everyone know she’s doing good.

"It is a little hard for me to express how the outpouring of love and kind words made me feel," Pepper wrote. "I do know that I am overwhelmed and grateful that so many people took the time to write a greeting. I feel blessed to have made it this far in life and I also feel blessed to have met so many wonderful people along the way. I’m feeling good."