Little screw on CP7 (purpose)

What is the purpose of that little screw on back of the CP7?

Is it safe to ground it for any possible electrical radiation?
I have a problem: https://www.ghielectronics.com/community/forum/topic?id=12065

I am almost sure it is made just for that. Can you try it and let us know.

I thought it was to keep the magic smoke in.