United States Postal Service
Someone posted on another scanning forum, a list of frequencies used by the USPS in Milwaukee in 2004.
Here's the list:
Security F-1 418.300
Security F-2 418.300/416.775
Airport Ops 418.200
Maintenance Ops 406.475 & 409.275
Truck Ops 166.225
Mail Sort Ops to Mechanics 410.200
Main - Supervisors 408.025
Others in use 407.175, 408.2625, 411.625
Postal Inspectors
Blue 1 169.650/170.175
Blue 2 169.650
Red 1 169.850/169.000
Red 2 169.850
Tactical 1 169.375
F-1 414.750/407.775
F-2 414.750
F-3 415.050/407.750
F-4 415.050
F-5 413.600/416.775
F-6 413.600