Creepy Glitch?

Something strange happened the other day while I was watching YouTube. I was watching a video and all of a sudden the video glitches and cuts to another video with a sound of an alarm like the National Weather Service. The video says something about the “boogy man” and “your worst nightmare.” It freaked me out and I exited out of the video. Then I looked at the same video on my phone and the glitch was not a part of the original video. It definitely wasn’t an ad either. I’m not sure what it was but it freaked me out. Looked like an amateur horror film. Has anyone else ever experienced anything like this? I know I sound crazy but it freaked me out.