Six days a week, in fair weather and foul, two dozen door-to-door salesmen, all of whom live clustered together in an apartment complex in Oak Brook, a suburb west of Chicago, pile into SUVs and cars and head into the big city, bent on sales of home security systems.

And on Sundays, their one day off, they drive together to the nearest house of worship of the Church of Jesus Christ of Latter-day Saints.