I don’t know if it also happens to you, but I always have this fear (not only the equipment but also the whole freaking house).
I have two Synology NAS devices and one “custom” server (just a PSU, a Ryzen CPU, two RAM sticks and a SSD).
Everything is grounded, on a compliant safety electrical installation, but I don’t know… I’m maybe paranoiac by nature.
My biggest doubt is about the PSU. It is a certified PSU (from Be Quiet! IIRC), that has more than enough power (500W).
UL rated, I don’t worry. There are a thousand other things which could and do cause fire. Hope you never have kids they’re a vastly more likely source of home fires as well. Your odds of being stuck by lightening are greater. And if you strip away the kitchen as the majority of home fires your odds of being stuck by lightening in a single year isn’t that far off. Yes this is a completely irrational fear.