Door Open Light Always Dim

I recently bought a used 2008 Hyundai Sonata Limited. I've been driving it for about 2 weeks now without any problems. I just took it out tonight for a drive and noticed the door open light was on, but not all the way. Non of the doors were open, and when they were the light turn on all the way.

I just turned the car off and the light is still on (dim). Any suggestions on what this might be and what I could do to fix it?