Earthbound spirits are not harmless. They can form attachments, if your aura is weak. Once attached, they are difficult to get rid of and can cause emotional problems. They will lie and tell you anything you want to hear in order to get into you.
Be very careful about what you open yourself up too. I've experienced a lot more horrible things then "faces". I wasn't looking for it. My aura was "cracked" due to some health problems and I've been trying to get grounded and have normal dreams again for several years.