What is the character ?
is a kind of “end of line” character – Unicode Character ‘ZERO WIDTH NO-BREAK SPACE’ (U+FEFF). \

Normally there are 3 common “strange” characters: EF, BB, BF.
How to remove the character ?
There are multiple ways to fix the issue. for example: write a java script function to replace the strange character to a empty string.
But, we think the most efficient way is using the free tool NotePad++ to convert the original file to UTF-8 (without BOM) format.
Menu
Encoding –> Convert to UTF-8.

After you did the converting, the strange space on web page will gone.
http://www.gogototo.com/resolve-the-strange-character-65279-in-wordpress-web-page.html