5 or 6 years ago I used to recieve phone calls from an unidentified phone number whose voice was a little girls that would ask to talk to her father. The conversation would usually go: "Is my Dad there?" "No." "Today I was supposed to talk to him."
At some point the little girl would hold the phone away and it would sound like she was talking to someone else who I could barely hear before she would continue the conversation.
"Do you know where he is? I need to talk to him. Could you go get him?"
At that point it would register in my head just how creepy and poltergeist-y it really was and then I would hang up the phone.
This had only happened 2 or 3 times within the year and the conversation never gone anywhere outside of this little girl wanting to talk to her dad.
Edit: This was usually around 2 or 3 Am.