Unfortunately, bathroom ventilation fans often are set up so that they exhaust air to the space between ceiling joists, especially if the bath is located on a lower level toward the middle of the house.
The United States Postal Service defines a postcard as: rectangular, at least 3 1â2 inches (88.9 mm) high Ã 5 inches (127 mm) long Ã 0.007 inches (0.178 mm) thick and no more than 4 1â4 inches (108 mm) high Ã 6 inches (152.4 mm) long Ã 0.016 inches (0.406 mm) thick.
While most people consider any card that goes through the mail to be a postcard, that's not the USPS definition. The only cards that are actually classified by USPS as postcards are cards (not envelopes) that: are rectangular in shape; and, are at least 3Â½ inches tall but no more than 4Â¼ inches tall; and,