I answered it and the guy on the other end said he's from Red Cross?  I assume he is asking for donation so I said I am on my way out and he said he will call back later..

Someone keeps calling me from this number in the late evening.

Red cross, yup!

These people keep calling and I don't know who they are.  Never leave a message and when you pick up the line seems dead.

this number called me at quarter to 9.... no message