Hello. Welcome to Just Answer.
This does sound like a case that calls for a complete rewire.
To determine whether a wire is de-energized, you can simply place a pocket tester near it, and it will beep and light up if power is present.
Do you need to see a link to that type of tester? A more appropriate name is "non-contact voltage detector".
As for finding someone to help you... if you trust Craigslist, that may be the way to go. There are many out of work electricians advertising on that site. I suspect most of them would be willing to work for a very fair rate.
If you choose to go that route, I would definitely ask for references first.
Another site that lists reputable contractors is Angie's List. They screen their contractors before allowing admittance to their site.
If this were a project you were planning to tackle on your own, there are plenty of experienced electricians here at Just Answer who would be happy to help with advice and guidance.
However, it doesn't sound like that's your intent, which is why I recommended sources for finding experienced help.
Another site you could contact is Home Advisor.com.
They also list contractors in all phases of home repair and improvement.
Rewiring a room at a time is a good way to go. If you are going to do that, I would not mix lighting power with outlet power.
I should ask whether it will stay in use as a nursing home, as that involves a whole new set of Codes that wouldn't apply to a single family dwelling.
It doesn't appear the chat is loading properly. Are you able to see this text?
I will change the question format from chat to q/a, which is more like a message board. That way, I'll know for sure you are able to view my replies.