SACRAMENTO (CBS13) — The U.S. Postal Service says mixups like the one that returned a package of marijuana to a Sacramento family they didn’t ship are becoming more common.

CBS13 brought you the story of the couple who received an airtight package of marijuana hidden underneath empty boxes inside a larger box.

The Postal Service dropped off the package at the home because it had insufficient postage, and the couple’s address was listed as the return address.

Jeff Fitch is a postal inspector for Northern California, and says his office gets several cases like this a week.

A quick search of the web shows what to do to sell marijuana through the Postal Service. Unlike FedEx or UPS, deliveries through the the U.S Postal Service can’t be opened without a warrant.

Postal Service: Pot Shipments With Fraudulent Return Addresses On Rise