How do you test for a bad GFI?

As a professional practitioner in the field of cryptocurrency and finance, I'm often faced with the challenge of ensuring the integrity and security of our financial systems. One crucial aspect is testing for Ground Fault Interrupters (GFI), particularly when it pertains to electrical systems that support our crypto mining operations. Could you elaborate on the steps involved in testing for a bad GFI? Are there specific tools or techniques that you rely on? Understanding how to identify and resolve such issues is paramount in maintaining a safe and reliable operational environment.