Adding Factory Trunk Light In My 67

Okay here is my latest. About 6 months ago I found a 66 trunk light at the local junk yard. I pulled out the light and wiring including that little 3 way looking plug thing where is connects to the trunk harness. I did NOT get any switch or button to detect when the trunk is open to turn the light on, should there be one?? How do I wire this thing in to come on when I open the trunk? How do I wire this stupid thing!! Does cars with trunk light have different wiring harnesses? Are 66 and 67 trunk lights the same?

Thanks For the help

P.S when you respond please keep in mind i am dumb when it comes to wiring :O

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Hot66ss

66 ss
67 malibu
Aces Member 2380
Team Chevelle member #262