PA system ext's

I thinks this is phreaking, Is there anyway other than trial and error, that I can find the ext to an intercom/PA system, if there is one?

Thx NC

depends on where you're trying to do it. If you're trying to get over a store intercom, then they have lil phones attatched to poles, and they have all the department extensions listed. If it's a school, you'd have to get into the office or wherever the central system is, and get into that…Ima try that one. I think we're gonna adapt a beigebox, possibly a wireless one, and hook it up to there and broadcast our own announcements and such. Iunno if that was any help to you.