I have these horizontal wavy streaks that flashes across my computer monitor...

[Michael W]

...can someone tell me what it is? I have a series of white shimmering, horizontal, streaks that runs nearly the full height of my computer monitor screen. it look something like when you are having minor trouble with the horizontal hold on the old television sets. some have said it could be the graphic card some say it is the monitor. I have one of the older monitors