rccraig, ouch that is a tough one! Our memories after 35 years are not the best!
I remember a movie that I just loved. Old B&W. It sounds a lot like yours but it wasn't an angel, it was death! Grandpa traps him in an apple tree. No one can see him but Gramps and his grandson. I have a feeling this is the one you are thinking of because the viewer doesn't really know it is death, he tries to convince the little boy that Grandpa is nutty and he (man in tree) is a wonderful guy. The little boy thinks the man in the tree is an angel at the beginning, but grampa knows the truth and slowly convinces others near the end of the movie that he did trap death in the tree.
The name of the movie is "On Borrowed Time" 1939, starring Lionel Barrymore, and Cedric Hardwicke. Here is a link to the plot summary:
On Borrowed Time (1939)
Let me know if you think this is it. By the way, if it is not, it is definitely worth watching. Wonderful movie!
