An employee who works on an irregular or occasional basis or is a special Government employee as defined in 18 U.S.C. 202(a) is subject to the provisions of the applicable subpart of this part when he or she is on duty.
Code of Federal Regulations
Example:
An employee appointed to a special commission or task force who does not have a regular tour of duty may run as a partisan political candidate, but may actively campaign only when he or she is not on duty.