Some of my neighbors have received a have received a (snail mail) postcard from a company called "EWS"

It's mailed as a delivery notice saying "We have a parcel for you". When the recipient tries to call the number on the postcard, the phone is either busy or the voicemailbox there is full. I tried to look up the company name online but I didn't find any information. I wasn't given the phone number that was on the card. Has anyone heard of this?