Spirits, ghosts, poltergeists, demons, etc. are non-corporeal beings residing in the 5th dimension which is right above our 4 dimensional Universe. Although a rare few might reside in higher dimensions. Either way they have to reach out from the 5th dimension which requires them to translate properties of their pure thought matrix into a format we can understand in our physical reality. To manifest in appearance they must will themselves into a pure energy state which is the next level after pure thought. This process trigger photons, the source of all light, to be created thereby causing us to see them.
When you hear sounds like footsteps or voices they must translate their thoughts into air molecule amplitude modulations to produce sound waves for us to hear. The footsteps might simply be a scare tactic although a confused ghost may actually be walking in the 5th dimension, and inadvertently sub-consciously translates that into sound in our reality. Spiritual entities may also produce smells that tend to be sulfur like in nature. Advanced beings like poltergeists, and demons can achieve telekinetic abilities across the 5th dimensional plane, and cause objects to move about. Some have the power to directly translate themselves into a physical body that may be like a solid hologram made of photons and the electromagnetic energy they possess. In that case they’d indeed make real physical footsteps. Luckily that rarely happens because these type of paranormal beings are beyond dangerous!
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