USPS customers have been left scratching their heads after finding a post office mailbox wrapped in plastic.

The top of the USPS box was completely covered, leaving customers unable to drop their letters inside for delivery.

The mailbox is located outside the Oak Forest Post Office on Judiway Street in north Houston, Texas.

“People can’t drive up and mail their letter,” resident Ricky Walschburger told CBS local affiliate KHOU of the odd sight.

“They have to go out and go inside to use the mailbox. It’s a big inconvenience.”

The box was later unwrapped but not before confusion and frustration spread through the community.

One resident, who didn’t want to be identified, was left wondering if the wrapped box had anything to do with recent mail theft.

She said a recent headache with USPS cost her thousands.

The woman said she dropped off multiple checks in the mailbox earlier this month.

“It had all the decals, it still had the pickup time listed, and there was no indication that it wasn’t working,” she said of the mailbox.

Days later, she learned the checks were never delivered.

And to make matters worse, she said at least one of the checks, worth over $13,000, had been fraudulently cashed.

“They did their best to make it look like my handwriting,” she told KHOU of the signature on the checks.

“That was a little disturbing to see.”

She had used the box to mail company checks on her way home, assuming it was secure.

When she reported the theft, postal employees reportedly told her the box had been targeted by thieves before.

She said workers at the Oak Forest post office even found a pile of undelivered mail still inside the mailbox when they opened it up.

“I was basically informed that’s a nonfunctioning mailbox,” she said.

“What sense does it make to have a mailbox outside the post office that isn’t functioning? It’s extremely confusing.”

USPS was forced to apologize but didn’t elaborate on why the mailbox was wrapped in plastic.

The agency also didn’t say how long the box was out of service.

“The Postal Service takes the security of the mail very seriously, including receptacles where customers deposit mail, such as collection boxes,” USPS said in a statement.

It added that the mailbox was “inadvertently out of service for a short time” but is now fully operational.

The agency urged customers to use lobby drop boxes or hand mail directly to an employee at the counter for added security.

It also advised customers mailing large checks to consider using secure money transfer applications instead.