"I did a huge amount of research," Gamble, 60, said of his effort to create a combination Mad Lab and science-fiction museum.
He estimates that there are more than 1,000 separate elements in the Mad Lab, including large electrical insulators that were salvaged from a Michigan power plant built in 1906 to run the Henry Ford Model T factory.
And there's more outside: An animated yard display features a cemetery with zombies and howling ghouls crawling out of graves; a large inflatable hearse, pirate ship and black cat; ghosts hanging from trees; a two-story-tall spider web; and thunder and lightning effects.
Gamble, who dresses the part of a mad scientist, has spent years assembling the antiques and buying the Halloween decorations to create his extravaganza. The yard display has gone up for seven years, and this is the second year that the Mad Lab has been open.
"The little kids really like this stuff," Gamble said. "Whole families come through to see what's new."
The outdoor decorations are free to view, while a trip through the lab costs $5 for visitors over 12 years old, $3 for kids 6 to 12 and free for children under 6.
Gamble said he plans to give half the money after expenses to a charity and use the other half to deal with his debt.
He has struggled with physical injuries and post-traumatic stress disorder since being shot in the head in 1993, when he was a 7-Eleven clerk, which has made it difficult to work, Gamble said. His financial condition worsened a few years ago when he stopped working to take around-the-clock care of his dying father.
Gamble a former member of the Utah Symphony chorus now runs two small businesses, one selling auto parts and the other producing audio recordings of choirs and other performances.
In addition to being a fundraiser, his Mad Lab is a labor of love. Gamble wants his creation to generate youths' interest in science and history.
"This is a unique display," he said.
Neighbor Marilyn Cutler said Gamble goes all out on his Halloween display and a lot of passers-by stop to look every year.
"There's a lot of scary-looking creatures," she said. "The neatest thing he has there is a big spider web. It's really quite amazing."
Visit the Mad Lab
The mad scientist's laboratory at 4970 W. Odell Drive (3570 South) in West Valley City is open for tours from 6 to 9:30 p.m. now through at least Sunday. The cost is $5 for visitors older than 12, $3 for children 6 to 12 and free for kids under 6. An elaborate yard display is free to view.