Hey, mayor! You've got some mail! Do you notice any glaring errors?

First Card

Front:

Reverse:

Second Card

Front:

Reverse:

Third Card

Front:

Reverse:

Answer Checker: Check

Hints: These puzzles have not been, shall we say, perfectly constructed. Each puzzle has multiple mistakes. When you've located all the mistakes, try correcting them by stabbing your pencil straight through the postcard.

Solution/Explanation