Random Movement on Units in Buildings

[kasual]

I've been searching and asking around the internet but I have not found a definitive answer to this question:

Q: If a unit in a building is affected by a spell that gives them random movement, are they forced to leave the building?

Just curious how this will be ruled at crossroads because I know it will come up in my games.

[kasual]

After some more thought, I believe they have to move out of the building. Nothing in the rules states that a random mover can not move and if their only move is out of a building, then that's what they must do.