Hmm... Not sure if I really think this is a riddle hun, sorry. a riddle is a logic puzzle of words that can have only ONE outcome. But I can think of a million things that fit to your specified criteria.
How far can you walk into the woods? What is it that has no weight, can be seen with the naked eye and if u put it in a barrel it would make the barrel lighter?
What runs around the house but never moves?!? Also, y did the golfer wear 2 pants(more of a lame joke than a riddle) Ok so there's a fat guy walking across a bridge but he needs 2 deliver 2 100 pound blobs across the bridge. He weighs 600 pounds but the bridge can only support 700 pounds...how can he cross in one try?!? Bob walks into a supermarket and sees a $100 but he also sees a piece of meat...y does he eat the meat?