I do not believe in the supernatural, magic, ghosts or anything like that. However, I can be very superstitious about tempting fate and won’t make jokes or flippant remarks that could be interpretted as such.
For example, my partner made a dark joke about how she’d rather have cancer than such and such. I begged her not to say such things, not because the thought of her having cancer upset me (although it did), but because it feels as if saying stuff like that could make it happen.
Mind and body are very tightly bound (that is how placebo works) I don’t think you are wrong to be wary of speaking disease into existence. The only sinus infection I have ever had, came after reading a particularly vivid and detailed article about how they start. Like my body was following along.
I do give my work computer enrichment activities to keep it happy. Listen to music so that it can have music, browse occasionally so it doesn’t have only work to work on. I get far fewer problems than my teammates do, so it seems to work even though it’s superstitious nonsense.