My experience when working in a university setting:
Work study jobs offered/assigned to those students that demonstrate need on the FAFSA.
Some of these students would put in as many hours as possible in the first semester to earn all of their work study award, then not work during second semester.
Campus jobs now have openings, financial aid office contacts students with work study $$ left to help fill these positions.
If campus jobs still need workers, the next list the fin aid office goes to is students who have applied for financial aid, but did NOT demonstrate need according to FAFSA. At least they made the effort to apply, their name is on file in the fin aid office, and they get next crack at filling work study jobs. The resulting paychecks are taxable income like any other job, but perhaps with the flexibility that on-campus employment provides.
Not every school may handle it his way, but contact fin aid office.