I saw this yesterday on a San Quentin State Prison sign shown during an MSNBC television program.

Problem:
A possessive apostrophe appears where it should not.

Explanation:
“APPEAL’S” of what?

The apostrophe in “APPEAL’S” should not be there.

The sign maker was trying to refer to the plural of the noun “APPEAL”.

He or she instead made the sign maker’s common blunder of inserting a possessive apostrophe when pluralizing a noun.

Maybe sign makers just love to create apostrophes?

Solution:
“INVESTIGATIVE SERVICES UNIT & APPEALS”