How To Wire Third Brake Light?

[mercurycapri]

My 82 mustang when I bought it had a rear spoiler from 86 or newer mustang which came with a third brake light. I would like to know how I can wire the third brake light. Thank you for any input.

 

[mercurycapri]

..

 

[89oem]

Here ya go

http://www.stangnet.com/mustang-forums/threads/help-with-third-brake-light.842238/