Hi, I know what your going through I had a female who when I opened the tank lid one day to clean her she scooted out and up the wall in the reptile room. One difference I could usually see where she was, but what a little stinker, she was darn quick and enjoyed her new found freedom, lol.

What I noticed was she would come down and sit on the other lizards strip lights when I was not in the room, I would catch her sitting there when I came in, I finally got a large fish net and caught her.
But what I would suggest is maybe have a strip light on over an open tank for him, any other light may burn him, leave food in there, put the tank up on a table near where you saw him in the rafters and hopefully he will be attracted to the light and food, (they are not stupid)

I sure hope ya get the bugger, lol. let us know, yeah a pic would be COOL, when he's back home
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PHEve / Eve