I'm looking and not seeing what you are talking about. The only " blue " is the line down your screen and that is a monitor flaw. Maybe if you circle the area??

The left arm looks to be holding a burning sword.

yes the left arm not sure what it is thanks for reply

Okay - since you said " Blue " ... now I see ( I hope ) what you are talking about.

Do you have any weapon mods that are " Ghost " - " Transparent " - " Bound Weapons " ??

Looks like it sheathed and did not ' vanish ' as most do - UNLESS - the specific mod you have states it will not do so.

yes my bad on spelling. yes got the star wars mod on with bound sabars but only ever used once. iv tryed using again to get rid of it but not luck. any ideas. thanks

Did you use this one ?
http://steamcommunity.com/sharedfiles/filedetails/?id=24194030&searchtext=light+sabers
It has a few errors in it when reading the mod page.

Try verifying your cache file:
Go to your Game Library on Steam and Control Click (Right Click) the game you want to verify. Select Proprieties.
On the Local Files tab you may be able to verify the integrity of game cache files you want.

yeah done that no luck

http://loot.github.io/
Try using LOOT. It will point out mod conflicts and errors.

http://www.uesp.net/wiki/Tes5Mod:Unofficial_Skyrim_Patch
You should get the patches as well. I am not sure if these will help you with your current problem, but it is always good to have them.

thanks will try it