Pittsburgh also will acquire a 2019 sixth-round pick from the Raiders, while Oakland will receive a fifth-round pick in next year's draft.
Switzer had six catches for 41 yards with the Dallas Cowboys last year as a rookie. He also returned 29 punts for 256 yards and a touchdown.
Switzer was traded from the Cowboys to the Raiders in exchange for defensive lineman Jihad Ward in April. Now, Switzer will be traded for the second time in five months.
Switzer was also trying to make the Raiders' roster as a punt returner, but he returned just three punts in three preseason games for a total of two yards.
The 5-foot-8, 185-pound Switzer was a fourth-round pick by the Cowboys in the 2017 NFL Draft.