CASTLE HILL — In the neon glow of the mad scientist’s laboratory, 32-year-old Shaynii Davidson does her best zombie impersonation. She tilts her head to one side, shuffles her feet along the concrete floor, and lurches around the room in search of brains.

Davidson was one of dozens of hopefuls who came to a casting call at the Bronx Haunted Warehouse on Monday and Tuesday night, hoping to land a role performing this fall at the spooky house, which is in its second season at its Castle Hill location.

“One, I love to act,” Davidson said. “And two, Halloween is one of my favorite holidays. To combine the two is just awesome.”

Held in a large industrial warehouse on Commerce Avenue, the Halloween attraction was launched last year by haunted house enthusiast Bobby Ferrera and director Timothy Haskell, who created and directs the annual “Nightmare,” haunted house on the Lower East Side. The project was dubbed “Z Day,” last year, but it's simply named the Bronx Haunted Warehouse this time around, and it's theme is a zombie apocalypse.

On Tuesday night, as a tornado watch was in effect for New York City and the sky outside the Castle Hill warehouse turned a menacing, blustery gray, Haskell waited for prospective actors. He’s looking to assemble a team of 15 to 17 people to play roles like the mad scientist, apocalypse survivors, and of course, plenty of zombies.

Haskell said he usually knows right away whether someone has what it takes to do the job well.

“I can tell just by shaking someone’s hand how energetic they are, what their enthusiasm is, how kinetic their energy is,” Haskell said. “It’s a great litmus for how they’re going to be in a haunted house.”

Koryna Ayala, a 17-year-old senior at Lehman High School, was trying out for the second year in a row. Last Halloween, she played a survivor who’d been mauled by the flesh-eating creatures.

“It was a lot of fun,” she said. “I had to lie on the floor covered in a blood with a whole bunch of fake guts hanging out.”

Ayala showed Haskell her best blood-curdling scream. She did a variation of zombie prototypes — the classic “Night of the Living Dead” zombie and the more modern, frenzied “28 Days Later” zombie.

“I don’t need you to be Laurence Olivier, but I do need you to commit to acting like something you don’t act like often,” Haskell said. “I need you to not be embarrassed by doing that, and I need you to, more importantly, have fun doing that.”

Haskell said the Bronx auditions attract a different type than those who show up to work at his downtown haunted house, where almost everyone is a professional actor or aspiring star.

“A lot of them are shy at first, especially up here, because they’re not actors,” he said. “Here it’s a lot of people who initially feel a bit timid to do something out of their comfort zone. So it’s important for me to loosen them up, and get them to be willing to call for brains.”

Samayra Rios, 29, who is studying to be a special effects makeup artist, acted in the house last year and returned to join the cast again this season.

“It was so much fun,” she said. “We’ve been waiting all year.”

The house itself is a maze of dark rooms and creepy scenes. Zombies, real and fake, are waiting around every corner to lunge at people. One room’s walls are covered entirely in children’s toy dolls, and an actor dressed as a doll herself blends into the eerie background before jumping out unexpectedly. Sensors in some of the walls give a static shock to participants who brush up against it.

“I had a 200-pound grown man run into the wall, bounce off, and then run out of the room,” said 21-year-old Janel Gonzalez, a part-time medical assistant who worked in the house last year.

For the staff, it’s often about more than just scaring people. They have to make sure the petrified haunted house-goers keep moving when they’re too scared to enter the next darkened room.

“I had a group of four people who just stood in the corner and refused to move,” Rios said. Another time, one flustered guest threw up at her feet.

Rios said the job is worth it, in spite of potential mishaps.

“It’s great interacting with people,” she said.

Haskell also warned those auditioning that it isn't always fun and games. The repetitiveness of the scenes can often grow tiring to less diligent actors.

“It’s a job, and you’ll realize that after an hour,” he said.

But overall, the thrill of giving a thrill is the ultimate goal.

“When you get a scream, it feels so good,” Haskell said. “It’s like getting a standing ovation.”