Recieving this phone call, will not leave a message

Someone called and ask for my wie but wouldn't leave a message.

called asked for my wife.  when i asked who it was he said richard, asked richard who..
said richard allen and really was wanting to get off the phone he hung up before my wife answered the phone
when it is called back  goes to voice mail that says just leave a message...

This person has been calling for over a year at odd times. He will not give his name or leave a message. He always ask for my husband by his first name and like he is an old friend. My husband and I have no idea who this is and from the area code we don't know anyone in that area. I always ask him if I can take a message and his reply is swift-No message and he hangs up. My kids have told him to hang on and they have brought the phone to me not telling him rather he was getting me or my husband. He hangs up. We are on the Do Not Call List and we keep that updated.

Individual calls, asks for wife by name, will not leave message. When we call the number back message received is "mailbox is full and no message can be left" then hangs up. Called twice within twenty minutes today.