LOUISVILLE, Ky. (WDRB) -- The knock echoes on the door in the middle of the night with a stranger on the other side dressed in everyday clothes. What do you do?

That person identifies themselves as an Amazon driver. They're holding a box but not wearing a company uniform, and their car has no markings bearing the online retailer's name. Do you open the door? Is it safe? 

This scenario is not hypothetical. It's playing out with customers in Louisville as the online retail giant works late into the night to meet the demand ahead of Christmas. 

"I mean, I am happy to get my packages. But I don't like it so late at night," Amazon customer Amanda Taylor said. "I do a lot of my Christmas shopping online with Amazon, and what I've noticed is it will say my package will be delivered by 8 p.m. There's no package by 8, but sometimes between 10 and 11, the package arrives."

Taylor is not alone in the hustle to meet the holiday rush and that record-smashing $65 billion in e-commerce expected in the U.S. in December. Amazon is delivering at odd hours. Other customers shared their late-night delivery experiences when asked on Facebook on Tuesday. 

"They tried to deliver a package at 10 to my house and I never heard a knock on the door," Kenny Arachikavitz said. 

Others posted responses saying deliveries have come at 9 p.m. 

Amazon representatives said the company utilizes a variety of different carriers to get customers their packages, from traditional carriers like the United States Post Office, to UPS and FedEx. Additionally, the company launched an effort of independent contractors who are their own boss and deliver through the Amazon Flex program.

Flex has caused some market confusion, as many times it's the "independent" drivers arriving in unmarked cars and everyday clothes after typical business hours. 

"That's concerning to me...," Taylor said. "I just don't know who they are, and it's usually a big white van with no labels."

Amazon said it vets Flex delivery drivers with criminal criminal and motor vehicle background checks. When asked if there was any cutoff time for that knock on the door, the emailed response said, "Delivery hours vary but only in rare circumstances do participants deliver past 9 pm. If customers are making orders through the Prime Now service, orders could be delivered up to midnight."

Barry Wilkerson, chief of the St. Matthews Police Department, offered some advice to keep people on both sides of the door safe during those deliveries.

"Obviously, you want to make sure whomever is delivering to your home is a bonafide delivery service or at least with the new flex service," he said. "Make sure they have at least ID, so you know who they are."

Amazon said its Flex app has a number of features available to participants, including a virtual ID drivers can use to identify themselves.

Wilkerson also recommends unmarked Amazon drivers on a later delivery park in the light, and the customer, if possible, should not answer the door alone. Before opening the door, Wilkerson suggests customers ask the deliver person to show the shipping label. 

"Have them show you the mailing address, so you can confirm it's a legitimate order you made," Wilkerson said. "Again, it helps you feel better that it's not a scam."

Proper diligence can keep a person with bad intentions from turning a fake delivery into a home invasion.

Copyright 2018 WDRB Media. All Rights Reserved.