adding electrical GFCI plug
Of course, the ground wire or 3rd wire is desirable &amp; preferred. If you can't ground the circuit or can't afford an Electrician to do so or to re-wire the circuit, then it's fine to use. A GFCI will work anywhere &amp; still provides protection without the ground wire. They're specifically approved for ungrounded old homes, but it won't pass a plug-in tester's scrutiny.

Here's a good article on the subject for your understanding.