OVERLAND PARK, Kan. -- A surveillance camera at a workout club recently caught some mysterious images when no one was inside the building.

Like the name implies, Anytime Fitness is open around the clock. The idea is that people can work in a workout at their convenience.

But Peterson said she has no idea what she missed when some mysterious images were recorded on Sept. 12.

"They're motion cameras. So I thought, what motion is triggering it? And we kind of got a series of weird pictures we could not explain," Peterson said.

Peterson said she knows there was no one in the building when the camera started recording.

"At 1:59, you see the last member of the night leaving," Peterson told Chapman. "It shows the street as well."

But inside the empty building there appears to be some kind of light.

"It starts at 2:20 a.m. and goes on until about 4:14 in the morning, kind of off and on," Peterson said.

Chapman reported that no one shows up outside of the building after the last man leaves, shining a light inside. And Peterson said lights have never activated her cameras before.

"(I) called the security company and they said, 'We don't know why that light would make the camera kick on, but it sure is interesting. Can we download a copy?'" Peterson said.

Peterson said some of her customers are having fun with the idea of naming the fitness phantom with Halloween a month away.

"I'm a very open-minded person. I'm willing to look at and consider any possibility. It's certainly nothing that frightens me," Peterson said.

The security camera records at one frame a second, so the video is a little jerky.