My roomate is taken naloxone inplace of saboxone. Is this safe?

Doubt it. Doubt he is using naloxone. Perhaps you mean naltrexone. If he is already taking the naltrexone, it is the single best med for him to be on. If he has not started yet, than this may be quite difficult and dangerous to initiate.
No. Your roommate sounds 'complex' and should not be replacing med a with med b; unless directed by a physician! have your roomie check in with his/her doctor a.S.A.P to reconcile the medical regimen he/she is supposed to be on; and then stick with it!