Ghosts... is it a being from another dimension?

We say that ghosts are spirits of the dead...
But how true is that?
Is it possible that they are not spirits after all?
Perhaps a being from the other dimension that can't adapt to our dimension and form a body...
So in conclusion, they turn into a energy orb, shadows or even a blurred image?
But when you think about it...
The Malays used to mention about Malam Jumaat which is actually Thursday night till Friday morning...
It is called a transition period between the netherworld and the real world...
But could it be that this period of time, it is not a transition period...
But perhaps a resonance of the vibrations between the 2 different dimensions?
It is plausible...
We couldn't say that it is confirmed that it is a resonance...
Perhaps, when we die, we didn't appear as spirits in this world...
But perhaps a being in the other dimension...
Perhaps they can exist there as another being which we can't assume what they'll look like...
Perhaps, they have the power to cross dimensions...
We can't say...
This mystery can't be solved unless we do prove something... If we do cross the dimension border...
What would we be like in their world?
Would we be their ghosts?
Which they fear so much?
No one is certain...