Yup--they are turn signal lights. They are wedged into the opening of the mirror arm. Its a bit scary but you can use a screw driver to pry them one direction, end wise and they will release. As I recall, its a sealed unit so you have to replace the whole thing, not expensive. Found the exact replacement at CW in their bulb/lens assortment.
2003 Alpine 40' MDTS
New Braunfels, Texas