When dealing w/ the spiritual there are no absolutes. Could be an angel, could be a demon, could be a deceased love one. The litmus test for myself would be:
-Does the message uplift and upbuild you?
-Does the content uplife or upbuild the one giving you the message?
-Does the presence seem familiar?
If the messages are uplifting and upbuilding it could be angels, deceased loved ones, or Ascended Masters's teaching you in your sleep. If the messages uplife or upbuild the giver of the message, it could be demonic.