In a world dominated by smarter and smarter gadgets, one of the dumbest machines on earth is making a quiet comeback.

Invented in the 1950s by an artificial-intelligence expert, the device is known as the "useless machine." It is typically a small box with an on/off switch and a hinged lid. Turn on the switch and a lever pops out, turns off the switch, then retreats. That is the machine's sole purpose: You turn it on, and it turns itself off.

Enlarge Image Close An 'advanced' useless machine with eight switches it turns off. Andreas Fiessler

Largely forgotten for a half-century, the useless machine is now finding a new purpose: entertaining a subculture of people who want to build their own. In the past few years, people around the world have created versions of the machine, boasting of their work with videos online.

Brett Coulthard was repairing Coca-Cola machines in Saskatchewan, Canada, for a living when he stumbled across a video and became enraptured. "When I saw it, I had to build one for myself," he says. "My friends thought I was off my rocker."

For the past year and a half, he has been running a business, the Frivolous Engineering Co., that sells kits to build the gadgets—enough of them that he no longer repairs soft-drink machines. For people who would rather not spend any money on a useless machine, Mr. Coulthard also provides free instructions.

"Useless machines" have been around since the 1950s. Now they're making a comeback on the Internet.

There are useless machines made of wood, Plexiglas and Lego parts. There is a very tall useless machine. One uses a furry paw to pop out and switch itself off. Another does it with a toy duck's bill. There is a useless machine battling another useless machine, turning each other on and off, over and over.

The brains behind the original machine is Marvin Minsky, a professor emeritus at the Massachusetts Institute of Technology. Back in 1952 as a graduate student, he spent a summer at Bell Labs, the intellectual hive known for cranking out Nobel laureates.

Mr. Minsky's job there was nebulous, he says today. "I got there and a manager said, 'Don't work on anything that will take less than 30 years—we like to take a long view.' "

On a lark, Mr. Minsky spent some time "inventing useless things," he says, such as a "gravity machine," a device that would ring a bell if the force of gravity changed. The bell never rang. The force of gravity is a "basic physical constant," Mr. Minsky, 85, explains.

He also dreamed up the useless machine, although the name he gave it was the "ultimate machine." His mentor at Bell Labs, Claude Shannon, built one and kept it on his desk, where the science-fiction writer Arthur C. Clarke spotted it one day. "There is something unspeakably sinister about a machine that does nothing—absolutely nothing—except switch itself off," Mr. Clarke later wrote, saying he had been haunted by the device.

Mr. Shannon built a few more and handed them out to people at Bell Labs. Those versions used little doll hands to flip the switch, Mr. Minsky says.

Eventually, Mr. Minsky and Mr. Shannon moved on to bigger things. Mr. Minsky today is a renowned authority on artificial intelligence and robotics. Mr. Shannon, who passed away about a decade ago, became a theorist who is considered a father of the digital age. He was also the father of a juggling robot.

Years passed. The useless machine never hit the big time, although it popped up here and there. In the 1960s, a monster-merchandise maker called Captain Co. sold a version, called the Monster Inside the Black Box, in magazines including Creepy, Eerie and Famous Monsters of Filmland.

A monster-merchandise maker called Captain Co. sold a version of the "useless machine" in the 1960s. The ad is shown on the bottom right. Captain Co.

That is when "The Addams Family" was on the air, with its disembodied-hand character, Thing, "intriguing everyone with the idea of a hand in a box," says Ed Blair, executive editor of Famous Monsters. A few years later, though, the gadget was gone, along with the television show.

But not forgotten. Michael Seedman, a partner in a New York private-equity firm, read about the machine in an article on Mr. Shannon, then built one. "I used to take it to places I frequented, placing it on the table," he says. People were hesitant to turn it on, expecting it to explode, he says. But it got a laugh. He called it the "leave-me-alone box."

Naturally, he posted a video, which inspired people across the planet to send him videos of their own machines. One is made from a suitcase. Another blasts out maniacal laughter.

Jim Gage, a teacher in Sweden, built one from a steel salad bowl he bought at IKEA for that purpose. The steel was "very difficult to cut," he says, "but I am a persistent man."

Martin Raynsford, a robotics engineer by training, sells kits with laser-cut wood parts in the U.K. A company called Solarbotics in Canada sells another version, offering custom engraving.

While the machine's appeal may be hard to fathom for some, one undeniable attribute is its energy efficiency. "It is a green machine," says Laird Sheldahl, a musician in Portland, Ore., who plays in a band named Dumb Machine. Dumb Machine says it is unrelated to the useless machine.

History is, of course, littered with devices that can make an argument for being pretty useless. But something about the purposeless purity of a machine so useless, it does nothing more than turn itself off, is capturing the imagination of tinkerers and thinkers alike. In her 2010 book "The Freudian Robot," Columbia University professor Lydia H. Liu writes that the useless machine reflects an "intuitive grasp of a fundamental problem of the unconscious that Freud has termed the death drive."

Dr. Liu says she doesn't own a useless machine herself.

There is even a "useless machine, advanced edition," with not one switch, but eight. It is the brainchild of German engineering student Andreas Fiessler.

Mr. Fiessler says he made his version from a broken desktop printer. When he posted a video of his creation, impressed viewers emailed him, hoping to buy one. Mr. Fiessler has made a few more, using other broken printers. "It's interesting how many people have at least one broken printer at home," he says.

Mr. Fiessler says he foresees an even more useless machine in the future, "as soon as I have an even more useless idea." Meantime, he has built a remote control duck.