Has anyone come across an option to find double lines in an imported sketch?
Do you mean two lines that are right on top of one another?
If so, the repair sketch tool may help:
2015 SOLIDWORKS Help - Repair Sketch
This may not be an option for you if you have a bunch of lines but you can cross select and check properties.
I'm assuming this is a an imported file that has been flattened from a a 3d wire frame or solid. In that case it might be easier to remove the dups in whatever program it came from. For AutoCad I used a lisp program called remove duplicates (or something like that). It was very effective. I would imagine there is something available within ACad by now. This was a long time ago.
Retrieving data ...