The House Opposite

The story takes place on Jowle Street in London, where many of the houses are empty. Ben, a homeless man with a rich sense of humor and "naïve philosophies," has taken up residence in one of the untenanted properties, No. 29. He is a reluctant sleuth, often confused by the strange goings-on around him. 

The House Opposite (1931) by J. Jefferson Farjeon is a thriller novel featuring the character Ben, an unassuming Cockney ex-sailor who becomes an accidental amateur detective when he witnesses suspicious activity from the vacant house he is squatting in.