A Rock Hill woman expecting a yoga mat in the mail got a very different delivery Saturday: 20,000 pills of oxycodone, valued at $400,000.

The woman, who asked not to be identified, told NBC Charlotte she had no idea why the pills were shipped to her.

“It's very scary. I'm shocked to hear it's happening in my neighborhood,” neighbor Erika Priscero said. “Being a mother of four boys, I would worry about one of them retrieving the package, opening it up and maybe popping one in their mouth thinking it's candy for Halloween.”

Drug agents said they’re getting a new call every week about drugs shipped through the mail.

“The suspects go around looking for vacant houses and have stuff mailed to the addresses,” Rock Hill Police spokesperson Mark Bollinger said. “They know if they mark it a certain way, the delivery people will just leave it.”

Agents said suspects also target homes that are usually empty during the day, so they can swipe the packages without the resident ever knowing. But this time, the victim was home. Investigators said they're grateful she had the sense to call them and report it.

“We feel good that we got it off the street,” Bollinger said.

Police said if you see a package sitting outside an empty home, contact the homeowner or police so they can come check it out.