A bit worrying - I had a similar experience just before 10am this morning. A guy knocked on our door and asked if a woman (can't remember the name) lived next door (he said he'd been trying to reach her for a few days). He wandered off when I told him I couldn't help.

I was in a rush doing other things, and didn't think clearly enough to really remember much about his appearance or even become particularly suspicious, but for what it's worth I think he was bald or shaven-headed, white, and wearing light coloured trousers or cargo pants. He spoke with a cockney accent.