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).
Well… while it is very unlikely for that to happen, if you want peace of mind, just install a smoke detector near your lab or anything that you suspect it can catch fire. That way you can get notified and call the firefighters Ina pinch