A team of Philadelphia real estate investors said a house they purchased was booby-trapped with a swinging knife that could have killed someone.

Uysaler’s ABC Capital Investments is accustomed to odd discoveries they buy distressed properties, renovates and sells them to investors.

“I come across this every day — abandoned dogs, homeless people squatting, drug houses with bags and scales — but never a trap,” Uysaler told NBC News on Friday.

A staircase inside the three-bedroom home was rigged with a line of string, running parallel and about 4 inches high over one step, he said. If anyone had tripped that string, it would have triggered a crutch with a knife attached to it to fall from above.

“If you lift your foot you would have caught that line, and the knife would have come swinging down to your throat or face.”

Despite the shocking discovery, Uysaler said the company is still going forward with renovations on the house — which had been abandoned for at least three years — that should take another four months.

Here’s hoping there are no further surprises in store for the investors.