Can belief without evidence be considered "rational"? Isn't what one considers "rational" subjective?

Believing in the possibility of ghosts is within the rhealm of rational thinking...science did prove that energy cannot be destroyed. After the vessle containing the energy is used up or destroyed the energy must go somewhere. Is that energy what we call a soul? Do some souls get trapped on earth? Who knows but a worthy concept...its less rational to rule out the possibilities.