Considering descriptions of the millions of abduction reports, what we think of as ET's are most likely demonic (their actions fit neatly within what is known of demonic possession and their message is always anti-Christian).
Sorry, but dismissing unexplained events in religious terms is a constant weakness of believers since the Dark Ages. Too many believers are so arrogant, that if they don’t understand something, it must be God or demonic.
Look at Pentecostals(my faith) and their past rejection of television and movie technology, simply because they didn’t personally understand why it works. That’s arrogance, not faith.