I presume by "research wise" you are referring to some kind of ghost-hunting tv show? Your statement that it is a draining activity and done from a different plane of existence is completely made up and has no basis in reality - just because you wish ghosts and spirits to be real does not make it so. Such things would have to be proven to exist before it is worth speculating over their physical properties.
Let's try the shoe on the other foot... could you please direct me to an unprecedented amount of claims where spirit activity "knocks over toilet paper"? I'll wait.
'Experiences' are flawed. When conditions such as schizophrenia and Charles Bonnet Syndrome (to give just two examples) have been PROVEN to exist, we KNOW that people can see and hear things that don't exist. Knowing that, what possible reason could there be to elevate someone's personal 'experience' over and above the fact that scientists, spiritualists, laymen, tv show producers et cetera have been unable to prove the existence of ghosts despite trying for hundreds of years?
You don't know, so your reasoning is pretty silly. The 'why would ghosts" line works for hoaxed YouTube videos where a toilet seat lid lifts 5 times in 10 seconds, but it only really works because you know (or are fairly certain) that the event was hoaxed. You can jokingly reason much easier this way. When the event is real however, reasoning based on ignorance isn't the best medicine for figuring anything out. It might be better to figure out what could have manipulated an object, other than a theoretical ghost. You might get somewhere better.
This reply of course theoretical and not researched, because we are talking about a theoretical entity and subject. That should have gone without saying.
'Why?' is a bloody good question whenever ghostly happenings are being discussed, because there is never a satisfactory answer. Why does my ghost keep turning lights on and off? Why does my ghost stand in the doorway when I'm trying to sleep? The answer from believers is "Ooh, just because. They're so mysterious, we can't understand why!"
Of course, rational answers are 1) You probably have an electrical fault somewhere in your lighting system, and 2) You most likely have a kind of sleep disorder.