IMO, & many ghost hunters, psychics, mediums, researchers etc agree, while the board itself isn't necessarily "dangerous" the doors or portals you may open & the type of communication you're attempting could get ugly. There are generally no "good" or "happy" stories related to Ouija use, almost always bad outcomes, people saying they wish they just hadn't even tried it at all.
Why take a chance & invite something $hitty in, you can't control what you're contacting or what wants to contact you for that matter.