DEAR ABBY: What does one say to casual acquaintances who stop by uninvited and with no prior phone call? -- NANCY IN AURORA, COLO.
DEAR NANCY: Let me tell you first what one doesn't say. It's "Come in!" It is perfectly acceptable to explain that the person caught you in the middle of your housework or a project you need to finish and, please, in the future to call before dropping by so you can make some plans together.