Passive income ideas are floated around the internet and television, and many times give people the impression it is very difficult to legitimately earn residual income.  As with anything else there is the good and the bad, but if you know what industries provide you the opportunity to earn residual income you can earn a nice living working this way.
If you are looking for passive income ideas that involve the traditional 9-5 work day then the insurance industry is one of the first places you will want to look.  There are different kinds of insurance agents, but the type that offers residual income opportunities is becoming an independent insurance agent.  
 passive income ideas
Independent insurance agents work for independent insurance agencies that represent several different insurance companies.  The agent is paid a percentage of the commissions when they write new policies, and when policies that they have previously written renew every year.  Once you have built up a good client base you can make a nice income from the renewal commissions that come in every month, in addition to the new business you will continue to write through referrals from existing clients.
Independent insurance agents are typically paid solely on a commission basis and listed as independent contractors.  This means you are basically in business for yourself(you split the new business and renewal commissions with the owner of the agency) and can make your own hours at work in most cases.  It does not cost the owner of the agency anything to have you there as you are not on salary, you just need to handle the customer service aspect of your client list and continue to bring in new business.  Most times as long as you're doing this you make your own hours and this career can afford you a nice income and an excellent quality of life once you have built up your client list.
If you are looking for residual income ideas that do not involve a traditional office job then there are still many options that are available to you.  The first is to become a freelance writer.  There are many sites that will have you write articles for them which they will then in turn publish online.  You are paid from the advertising that is placed on your articles(the commission generated from the clicks on advertisements within your articles will be split between you and the site that you are writing for) and the better quality content you write the better chance you have to earn residual income this way.
Freelance writing this way is a great way to make money because you are in complete control of the hours you work, whether or not you choose to work from home, and how much you would like to write.  All sites have their own system of payments, but it is important to remember that there is no guarantee of income just because you write something and it's online.  You will need to write quality content that is more than two or three paragraphs.  However, there are people who have been freelance writing who put in a genuine effort and make thousands of dollars every month doing it on their own schedule.  If you can learn to be a good writer, and write content that people are looking for, then you can certainly earn good money this way.
One of the residual income ideas that is most overlooked is selling information online, such as writing an Ebook.  Almost everyone has at least one topic that they know more about than the average person, and that is all you need, a better understanding of something than the average reader online.  It may be playing pool, how to fix a cell phone, or how to pick a good dog from a shelter(use your imagination, there are nearly limitless ideas to write on).
 residual income ideas
There are companies that will set you up with a website to sell your Ebook, and will also promote it for you for a small monthly fee(making sure you get visitors to your site).  This is not nearly as expensive as many people think.  These companies will handle all the technical aspects of getting your website up, and putting up a payment system for people to buy your Ebook, so all you have to worry about is putting together the best book possible.  This is a great way to earn residual income because you will get to keep a larger portion of the profits that you make from your sales.  You can find information on companies to help you build your site by entering "build an Ebook website" into any search engine.
The methods listed above are some of the best in terms of passive income ideas.  Like all good things they do require some effort on your part to get up and running, but if your willing to put in the work you can reap the financial benefits for many years to come.  

The Moonlighter's Guide To Online Writing