"Alignment grid" suddenly showed up on my desktop I am on OS X 10.9   Yesterday, an "alignment grid" mysteriously showed up on my desktop.  How do I get rid of it?



The grid lines don't show up when I do a proper, OS X screenshot. So I've taken a picture of my physical monitor, an Asus monitor, to show the problem.
As it turns out, the problem is with the monitor (Asus in my case), not OS X. You should be able to reset this - i.e. make the grid disappear - via the monitor's menu 'System Setup'.