CHARLOTTE, N.C. -- Chances are, you're likely to have received a postcard in the mail saying the person sending it needs to "urgently speak to you."

There's a new one that's making its way around Charlotte that's caught the attention of the Better Business Bureau. The mailer provides a phone number, telling its recipient this is the "third notice" they've received.

The return address on the back of the card is a post office in northwest Charlotte, not a business.

"The postcard, the mailings that they use are not as transparent as they should be," said Tom Bartholomy with the BBB.

So who is the sender? Are they doing anything illegal?

The BBB said it's a company called Real Estate Busters, and even though they aren't as straightforward as they should be, they're not breaking any laws. The company is looking for houses to flip, and are probably counting on the vaguely threatening language to get people to act.

"Fear is a very powerful motivator for customers," Bartholomy explained.

While this company may be legit, others aren't. Sometimes, scammers will send out extended warranty notices that look like they're coming from an automaker or even the government. You're told to act immediately by calling an 877 number, dip into your bank account and extend the factory warranty on your vehicle.

Experts say to look for things that make the letter official. If the letter says it's from the "motor vehicle division," that's a red flag. So at the end of the day, how can you protect your identity and hard-earned cash?

"I would just do as much research as you can," Bartholomy said. "If you can just Google the phone number, you can come up to the BBB."