To add voice, try taking on a perspective from the Salem Witch Trials. For example, are you speaking from the perspective of an average citizen at the time? A religious leader? A person accused of witchcraft? How would they all describe it differently? Thinking about the different ways those perspectives would describe the historical event will help bring voice into the sentence.
Also, a large part of "voice" is actually writing style, or the aspects of your writing that make it unique. You may want to try bringing more style into this sentence. I would think about changing up the structure of the sentence and the vocabulary to insert more of your own voice. You could lead the reader into your point by starting with a scene or imagery from the Salem Witch Trials that showed how dangerous it was. You could also change the word "dangerous" to something more unique, like "brutal", "deadly", "terrifying", or "treacherous".
Hope those ideas help!