箱信 - Belief

Traditionally, Chinese characters were written and read from right to left.

In this picture, if you read the Chinese characters in red from right to left, you would read 信箱 (Mailbox), which is exactly what these boxes are.

But then, if you read from the left to right, you would read 箱信, which sounds exactly the same as 相信 (Belief).

=P

箱信 - Belief, originally uploaded by SJern.