Green Lines on Dell Inspiron 3800

I have a Dell Inspiron 3800 and I have a seemingly random problem that comes for a couple months and then goes for a couple months. I think the problem tends to come more in winter but I cannot verify this. But sometimes in the year my monitor works absolutely perfectly. Its weird because the problem will be there for a long time.... then I'll be sitting here and it'll just stop! Right now the problem is occuring, however. The problem is that I have green lines that appear faintly all over my screen. The lines tend to move and wave a little bit with different pictures. They run vertically. I don't know if this is a hardware problem. Anyone heard of something like this? Any ideas of what the problem might be? Thanks a lot!

Kevin