In one of the more extreme circumstances (this has happened a few times), the messenger is not even aware they are being used as an instrument, and may also forget after the fact (even more strange when you meet them again and they have no clue who you are). But once they become aware they have been used as a messenger instrument, not only has the contact been corrupted, but I've seen the instrument/medium get corrupted by other entities as they start allowing or seeking more contacts. One medium actually went so far off that they lost their abilities, assuming they got "switched off" for their own good, which they don't seem to understand.
Making contacts isn't inherently dangerous, but it can quickly slide in that direction if unaware of the spiritual battle being waged.
Making contacts isn't inherently dangerous, but it can quickly slide in that direction if unaware of the spiritual battle being waged.