What is the reason only the drives side head light would come on and stay on.

What is your question?

I noticed the head light came on over the weekend and it stayed on for 30 seconds and then went out. I had been leaning on the car and thought maybe it was the alarm system. The morning my neighbor called at 6 am and told me the drivers side light was on. I tried the key fob from the house and no change. I went out and moved the light switch to every position, no change. I started the car and moved it and when I turned it off the one head light stays on. The only way to get it to go off is to disconnect the battery.