Often the telephone line leaves the elevator shaft at a "mid-point box". This is (obviously) at the middle of the run. In a 15 story building it would be on the 8th floor.

However, I have often seen them on the top or bottom floor too. As to where it goes in the elevator machine room? You're going to have to get the elevator company down there and ask them.

Tracking it back from the telephone room is a good bet. Get yourself a toner and a wand. It'll help a lot.

Sam

"Where are we going and why are we in this hand basket?"