In regards to Ouija Boards and EVP's, there was possibly at some point a forum here on it as well as chatter in recent days on Twitter about it as well. There was also discussion on Twitter about spirit communication using flash lights.
Ouija boards are quite different from EVP's and for the main sake of safety, I discourage folks from using them as an entertainment value. In my eyes, that is wreckless behavior; but no more so than instigating a spirit or using other forms of communication with the spirit world - scrying, channeling, seances, etc.
The bad rap that many of these venues have received have come from people who are absolutely clueless or are narrow-minded in regards to the spirit world. In addition, kids as well as adults who are looking for a good "scare" often open doorways that they have no idea how to handle. They take no precautionary measures or invoke any type of prayers or other means of protection.
With that said, EVP's are merely a way of grasping a response from the spirit world. In my experience with using EVP's, it is not only a form of validation but also a way to try and understand the spirits presence. Ghost boxes are another branch of hearing responses. I would disagree with someone who would state that EVP's or Ghost boxes are dangerous. It is merely like a "telephone" to the spirit world; allowing us to hear what they might have to say.
Regardless of how communication is sought, remembering that common sense should always be a must and throwing careless regard to the wind is what is dangerous. It doesn't matter if it is an enthusiast or a seasoned medium/sensitive/empath/investigator. Having an understanding of what you are doing always helps and if you do not know what you are doing, seek out the help and/or advice of someone who does.