Is this normal for your voicemail greeting to do?

I have a custom voicemail greeting on my iPhone. I wanted to change it back to the default but before I did I wanted to listen to my custom voicemail greeting one more time before taking it off. When I pushed play it was suddenly a new custom greeting but it was not me and didn't sound like anyone I know. I'm confused and now left wondering how this happen?

Someone you know might have changed your voicemail greeting as a joke, if they had access to your phone.