An easy way to find out if there are people on your campus who are interested in becoming an advisor is to go to your Greek Life office and ask. Sometimes there will be newer (or older) staff or faculty who have asked about Greek Life or expressed some sort of interest that you director can hook you up with. I would strongly recommend sticking to someone who works in the college environment to be an advisor for you rather than someone from outside (either from your school or from one nearby) since they will be able to help you with connections on campus and will be much more easily accessible.
As sad as it sounds, try to find someone without a young family because they will be able to devote more time to your group and will be able to be random places at random times for you
If your greek life office can't help, try your student organization/leadership office or undergraduate affairs (whatever they are called on your campus).
If you still haven't been able to find someone who is interested, do some research and find out if any of your professors or staff members were in a sorority or fraternity. If you find on that one of your members is close with, approach them and see what they say about helping out.