Question Unidentified metal spring loose in case

[V Cyberpunk]

I opened my pc and found a metal spring loose in my case, little smaller than a coin and I want to know where it is from.
My pc:
i5 4460 with cooler box
H81M-S1
2x4GB DDR3 1866 Mhz HyperX
GTX 1070ti Zotac
HDD WD 500GB
SSD Sandisk G26 240GB
PSU PCYes 430w
Case Vinik Twister VX

here a image: http://imgbox.com/VXBxmcjU

 

[Zephyl]

Might have come from some moving part of the case, or under one of the screws from a CPU cooler. (Though it looks a little thin to be the latter)