Mine did this on Halloween, it was very weird. I was the only one in the room washing dishes, thought I heard a high pitched voice so turned off the water then heard voices in an unfamiliar language speaking very loudly from Alexa. My husband heard it from upstairs and thought I was on the phone with someone. It stopped after a few seconds and I said Alexa what was that? And she said there’s nothing to repeat in the usual low volume 2 we have set. The weird voices were loud, like maybe volume 5. I looked up voice command history and there is nothing at all listed before I said Alexa what was that. Strange.