While the library does not own practice material for the Westchester civil service exam. There is material available online from the New York State Department of Civil Service.  According to the Westchester County Human Resources page:

The guides provide a cursory view of format and content to help applicants prepare for the indicated exam. Please refer to the NYSCSC's Web site above to access the most current version of study guides offered.

Civil Service Test Guides for New York States