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).
I’m sure everything I am currently running is safe, but I have that fear also, ever since one of the PSUs in one of my R320’s died and smoke started poring out the back (blown cap I think) - hasn’t happened since, but it’s one of the things I worry about