

OP, it’s fine to believe in whatever you feel like it, and IMHO ghosts and aliens are better beliefs than some other options.
With that said, I think it would be better to say that you believe those things and use the “not 100%” as a justification.
There is no way to gather all evidence about any topic, so we need to define what is acceptable as “enough” evidence and what “make sense” according to what we know; at least when we (as a society) talk about science.
Now I’m thinking about it, “make sense” to not have sound in your dreams. As your eyes are shut down, keeping your ears available to detect danger seems an advantage to be selected. And that fits with my experience where the sounds I can remember were real.
But there are others known examples of sound inside dreams: musicians! Many songs were written in dreams:
Purple Haze (Jimi Hendrix)[Inspired by a dream, not “composed” in a dream]Sweet Dreams (Are made of this) (Eurythmics)Edits: corrections