on waking from sleep, "One should be mindful to wash his hands three times in order to remove the evil spirit (ruach ra'ah) that lingers on them" (Shulchan Aruch)The midrash (agadah) have reference to evil spirits. But that is not theology. The theologic (halachic) texts do not have this concept.
I am giving you the honest answer.
ruach ra'ah is female, "She insists on remaining on the fingertips until one washes them three times" (Shabbat 109a)
one should not touch his mouth, ears, eyes, nose, anus and penis before that, for fear of transferring the evil spirit to those orifices
water which has been used (and thus contains the evil spirit) cannot be poured away inside the house or in a public place, or used for any other purpose