The caller left no message.

Robocall.  No one from the calling party spoke.

Calls and hangs up. says nothing

young man, said grandma this is your grandson did mom tell you about my trip?  I said what's my name, there was silence then he hung up.  I knew this was a "scam" call and wanted to see just how far he would go.

called me once, left no message,  number shows up twice on my redial list.  i never dialed the number