Probably two things led to the creation of this. The first was the lack of decent fonts when making digital versions of ghostbuster nametags in my work over the last few years... people used varying font styles (AdamAKAMoron used the 'Ghostbusters' font for his) but none ever looked quite right...
The second was actually a request by Sebastien Clavet himself, requesting knowledge on the font. And as it was speculated that it was probably just a custom one the costume department did when making the uniforms for the first movie, it seemed unlikely that we#d ever find a 'real' font that was identical to the one seen on screen.
Hence, 'GB Nametag' TrueType font (V 1.0). Can be scaled up or down, given custom colouring and should work flawlessly within Adobe Illustrator. Some notes included in readme.
The only legal issues that might come to mind are to the creator of the nametags, but I don't know their name and it's been 20+ years since they first appeared and so are probably covered by Public Domain.
Uploaded a more professional preview image.
Just for clarification, the actual font is the white lettering, the red nametags are what you can do with the font and Photoshop.