Can Earthing trigger intensely frightening dreams?

I gave an Earthing pillow case to a friend who suffers from adrenal fatigue and insomnia, and the first time she used it, she had a terrible experience. She came into semi-consciousness in the middle of the night, convinced someone had broken into her apartment with intent to kill her. In the long, vivid "dream" that ensued, she moved about her apartment and saw signs of violent entry. There were many other high-anxiety, deeply emotional components of her experience. It was chaotic and terrifying. She came to full consciousness in the middle of the night, exhausted and extremely disturbed. She checked her apartment, feeling very unsafe for the first time in the two years since she's lived there. It had never even occurred to her to feel unsafe before. There's no way she'll give an Earthing product another try. Does anyone have any insight into what could have triggered her experience?