Probably not, but what you definitely DO need is a healthcare power of attorney (incase you cannot make decisions on your own) and a Living Will (telling your instructions about prolonging care at the end of your life). You do not need an attorney to do these powers. In fact, the management of your continuing care community should have them right in their office, and they can witness them for you. But each state has its own form, so make sure you don’t just get the forms off the Internet. And don’t procrastinate.
Also, are you sure you have nothing to leave to anyone? Perhaps some historic mementos or personal items that you want given to someone special? If there’s no money involved but you want to designate things it won’t be an official will, butyou can leave a letter with those wishes and have it notarized at the same time you sign your Healthcare Power of Attorney and Living Will.