Well, the short answer is YES because you might electrocute yourself if you try and do the work yourself!
The long answer is that it is in fact illegal for an unlicensed person to carry out electrical wiring work – even on a residential property. The legal definition of electrical wiring is very broad so, for anything more complicated than changing a light bulb, you really do need to use a licensed electrician to do the work for you.
Electricity is dangerous. Using a licensed electrician reduces the risk of you harming yourself while carrying out the work, and of someone being electrocuted later because the electrical work does not meet safety standards. If that’s not enough reason for you, incorrectly installed electrical work also increases the chance of a house-fire.
If you’re a landlord you certainly don’t want to run the risk of being responsible for the injury or death of a tenant because you were trying to cut corners and save a bit of cash. Even if no one is harmed, you can be fined $22,000 as an individual, and $110,000 as a company for carrying out unlicensed electrical work.
It’s just not worth it. Always use a licensed electrician. You’ll probably save money in the long run, and possibly your own life.