Here are some great examples of Ectoplasm trying to form into apparitions. 

These 2 photos were taken outside an old boarding house in MA.  It was a clear night and this is real ecto, not breath or exhaust, etc.  The home was used in the underground railroad in the 1800's and was purposely built  close to railroad tracks that are still used today.  A little girls was hit while playing near the tracks and brought into the house where she died.  There are remnants of her dress in the attic.

Some incredible ecto captured in a cemetery in ME