A few thoughts:
Black Witches [who try to blow up churches, or whatever], are not real witches, but people who want to be purposefully offensive to christians, . . . probably their parents.
Wicca has a God, Goddess, and many have angels they use for "the quarters".
Wiccans do not believe in a "completely evil entity called Satan", as that is a christian concept.
Going to view a ceremony will not invite anything "evil" into your life. You have to be willing for that.
My brother, and his wife, are "witches" and I have sat in on a ritual before. I found nothing interesting about it, . . . .except maybe the candles, but I really like fire. I felt nothing "evil" at all. I've seen a few of them, in fact. I also had a moment when I [along with them and a couple they do the rituals with] messed around with an Ouija board. I felt nothing, even though the pointer moved, . . . I was convinced that someone there was doing it. Even if not, I sensed nothing . . . . . it was relatively uneventful.
After experiencing the rituals, I really didn't find anything in them that spoke to me, but my brother is into it. He was a christian, like myself, long ago, and told me that he started this path because God told him to, . . . the same voice he heard as a christian in church. I question that, but that was his experience.
But I like some aspects of Wicca. I enjoy the working of nature in their rituals, the candles, occasional bon fire, taking the time to reflect on yourself in what you want to get rid of [negative traits], and working on bringing in the positive ones. It isn't my path, but there are aspects of it that are kind of wonderful.
All of this just to state that when anything that isn't "christianity" is looked upon with SUCH a negative eye, how can you ever see the true good?