Oh dear, oh dear. Here's some information you are apparently missing about the real world. A physical thing can have an effect on other things, and those effects can be observed, leading us to state that the physical thing really is a physical thing and does actually exist. Anything that has an effect on something else is a physical thing. If a thing is "non-physical" that means it does not have effects on other things. It therefore makes absolutely no difference to the rest of the world is that thing exists or not. It is completely pointless to assume it is real because not only is there no way of ever finding out, but there are absolutely no consequences of it existing.
If a thing exists, it can be measured. If a thing can be measured, it exists. If a thing is "non-physical" it cannot be measured and therefore does not exist.