This is a weird one, but I think it's cool...
This is from the early years of the park, but I'm not sure how early. If you were riding the Skyway and purchased a round-trip ride rather than one-way, you would carry this sign with you on the journey, hand it to the operator on the other end, and s/he would leave you in the vehicle for your ride back to the Fantasyland chalet or Tomorrowland station.
I am not fluent as others in the way of tickets. Were the ticket book tickets and ticket machine tickets for one-way or round-trips? Did it take two one-way tickets to equal a round-trip? Definitely leave a comment if you can clarify.
****To clarify a question on the comment board, this piece isn't techinically a ticket. It's a hard-card mini-sign (about 6 inches by 4 inches). Thanks for VDT for clarifying the Skyway ticket situation. I guess this sign was a special way to identify people who bought a round-trip ticket, since one-way was more customary.