What is the ruling of Islamic law regarding the stance of the refrigerator owner and what is incumbent upon him towards the doorman after the doorman's son died from an electric shock from the refrigerator, which was placed as an ongoing charity (Sadaqah Jariyah)?

It appears that the owner of the refrigerator is not liable for anything, unless he was negligent in bringing in expert technicians. As for the technicians whom the doorman brought, they are liable for diyah (blood money) and kaffarah (definition) (expiation) if they did not perform the work properly or made a mistake in the installation. If the cause of death was something else, such as the boy tampering with the electricity after the technicians had completed their work perfectly, then the technicians are not liable for anything. The summary is that no one bears responsibility for a death that occurred unless they caused it or were negligent or remiss. The doorman should be consoled if it is proven that the refrigerator owner was not remiss or negligent.