Operating a Bed & Breakfast
It's the ultimate home business: Your home actually becomes your job. Running a B&B can be ideal for retired couples. Between the two of you, most of the skills needed -- cooking, maintenance, interior design, marketing and a cordial way with guests -- are probably covered. This career offers many opportunities to meet interesting people. Usually a seasonal business, it can give you ample free time during slack months.
The hospitality business is not for everybody. You have to like getting up early in the morning. You need to be well organized and good at multitasking. You'll have to keep your home neat all the time and interact well with people. A keen business sense is a big plus.
Some new B&B operators use their current homes. The kids are out of the house and they've got the spare bedrooms; it's an easy solution if it works for you. Another option is to buy a large house in a good location and convert it. Or you can invest in an established B&B.
Be sure you clearly divide the duties and responsibilities between you and your partner. Otherwise, one person might end up doing too much, or duties will fall between the cracks. Putting it in writing doesn't hurt.