C# Deleting a randomly file

So I have this very interesting program in mind that when i press a button, it deletes a random file in a specific folder (for example, let's say the folder: "C:\Users\User\Desktop\test") Let's say i have 20 files in this folder and each time I press the button it will delete 1 of those files randomly Extemsions should not matter.

I need this for further research in C# and would have no clue where to start, nor have i found ANYTHING similiar on internet like this. Feel free to help. Greetings Luna