what is the best approch

In direct relation to “mailcarrier” topic without hijacking it
I work for the BROWN Co as a delivery driver and I am always at homeowner’s door. I know of many houses that are in need of work or not maintained. I also know some that over the years the owners have gotten older ( takes them longer to come to the door) and are unable to keep up with the maintenance. My question is this: how can I politely ask him if he has any intention of selling and moving without getting him upset? I am hesitant of doing this simply because they are my customer and I will see them again. I once asked one owner if he knows anyone in the area is thinking of selling and I was politely rebuffed. I thank you for your opinion and excuse my misspelling

This is a touchy subject… you may want to tell them that you are looking for a house to buy and ask them if they know any houses in the neighborhood. Tell them you are looking for a house like theirs. If they are considering selling, they may tell you.