are you using just the standard video cable, or do you have an extension on your video cable?
I have a monitor at my shop, which nessecitated an extension on the video cable ... being the cheap person that I am most of the time, I just grabbed an 'el cheapo' video cable, and now my display has ghosts. one of these days I'll upgrade to a proper shielded and choked cable, but for now, it gets the job done
ok, if it's not an extension cable giving you a problem, maybe your colors have gotten out of alignment somehow? Most monitors don't have an option to align the colors, but all three of my Sony Trinitron (from last century) have the option... if your ghost is orange, maybe your blue color has shifted somehow, and needs to be lined back up... this is going to be in your OSD Menu somewhere, if your monitor supports it - consult your manual for the specifics.