I looked through NPD and see your problem.
They call it a "Glove Box Light" but if you look at the fitment it says:
1967-1968 MUSTANG W/ FLOOR CONSOLE
1967-1968 COUGAR W/ FLOOR CONSOLE, EXCL XR-7
1964-1965 FALCON GLOVE BOX
On a 67 it goes into the console and not in what we think of as the glove box.
Nothing goes into the hole in the glove box.
The glove box light is part of the Courtesy light group and includes the glove box light, underhood light, trunk light and on hardtops includes underdash and courtesy light.
It is not a part of the interior decor option.