Question I’m hearing electrical noise coming from an open-case custom-built PC

[reasoning]

These are my specs.

https://imgur.com/a/abMBNNO

View: https://imgur.com/a/abMBNNO


Recently, I started hearing a almost constant sound of electricity static from my PC. It has an open case, which makes it worse. I did a 15 minutes OCCT power test and nothing was unusual.

I'm going crazy about this. Please help

 

[Ralston18]

Be very careful.

Make and model PSU?

Wattage, age, condition (original to build, new, used, refurbished)?

Are you able to identify the source/location of the static noise?

Does the noise stop when the system is off? Or, if not, when the system is unplugged?

Why is the case open?