Just because the 1099-MISC is only in one name does not necessarily mean it is only the wife's income. You need to determine if they each have a separate business, or if they have a Qualified Joint Venture (or Partnership). You already said it is a "husband and wife" business, an it seems like the husband is showing properties without the wife. That seems like he is part of the business, and it likely could be a Qualified Joint Venture (or Partnership).
If both have separate business, or if it is a Qualified Joint venture, a Schedule C should be filed for each of their incomes. Obviously a Partnership would require a separate tax return.
Because the 1099-MISC is only in one name, for most Qualified Joint Ventures I start off reporting everything one Schedule C. When that is finished, I look at the profit and multiple that by 50% (or whatever their ownership percentage is) and on the wife's Schedule C I enter that as an "other" expense called "QJV: Allocated to spouse". Then I do the second Schedule C for the other spouse showing that income (and no expenses, because they are all on the other Schedule C).
