In these situations, Kendra, it's common for people to confuse two completely different questions........
1 Ist it legal?
2 Is it sensible? (i.e. safe)
The legality is immaterial. So, is it safe? Who knows? That's the point. Your husband is perfectly capable of making the connections. Even an electrician will tell you it's not a difficult job.
What you don't know is:
Is the cable the right size? If so, how is it routed. It may be installed in a way that reduces its current-carrying capacity. It may be impossible to tell, but a couple of tests will give you some idea.
Is a functional Earth present? The Earth connection may have been lost years ago. You wouldn't know until there's a fault ........... and the circuit does NOT disconnect properly in the way that it should.
Sorry to sound all po-faced and preachy, but this comes up quite often. Even a voluntary Q&A site has a "duty of care" of sorts. It may not be legally binding, but this does bring me back to my first point above ....... it should be, at least, sensible.
The simple tests that an electrician would make, take very little time. No huge bills.