mistaken is easy and unambiguous so better use this word only. Still, if you want other ways to say that, here are they...


  A: I think I heard something in the dark. 
      B: I didn't hear anything. 
      A: Maybe, I was mislead about that sound. OR Maybe, it could be something else! OR Maybe, I misunderstood it as some sound.


To avoid ambiguity, I'd prefer the second one - Maybe, it could be something else (not sound). 

What is another way to put "mistaken about what one saw"?
A friend of mine picked up a Pioneer "Dream PC" for real cheap at a charity sale, just because it looked strange. But it did not come with a power cable.

Any idea what this type of connection this is? Or any other type of device that uses this type of connection, so we can try track down a cable for the machine...


