At the start of the round, a few people are chosen to be runaway prisoners from the Space Wizard Federation, and there will be a Wizard announcement announcing their presence of the station, demanding that they be handed over to them, preferably alive, before a certain time, or they will send in multiple wizards to destroy the station. The Space Wizard Federation has provided a small shuttle for bringing prisoners to their ship.
The runaway wizard prisoners are given access to the body swap spell and perhaps one or two more that are independent of gear and that would help in escaping justice. There would need to be something to encourage the runaway prisoners to steal bodies somewhat often, I'm thinking this could be one or more of the following:
Every once in a while, command receives a fax with some clues pointing towards the current identities of the wizards. Harder for the wizards to know when to swap bodies.
The Space Wizard Federation casts a spell on the station that causes any body that has been host to the soul of a wizard for a certain amount of time to give off some visual effect until said soul no longer inhabits the body. Probably harder for admins to manage.
The wizards are given additional objectives that would require use of their abilities, thus getting the attention of security.
If someone who is not a runaway wizard prisoner is handed over to the Space Wizard Federation, they will be returned as a cluwne, but this will only be revealed if it happens.
(Big thanks to Trulyabruh for helping me brainstorm this.)