I have a Force FX lightsaber that I have been trying to hang for a while, then it just hit me. I have guitars on the wall and they all hang in String Swing holders. I had an extra one, so I tried it out as a lightsaber holder. At first the saber wouldn't stay in as the opening is too wide, but just using my grip to gently close the gap a bit and it is perfect. I will have to get photos up for reference but I am not near it right now. It is cheap and since they have rubber coating to protect guitars they will not damage your saber at all.
String Swing CC01K Hardwood Home & Studio Guitar Hanger (Shades May Vary):Amazon:Musical Instruments