Apple - Can a 3rd party charger damage my macbook pro?

It's unlikely they will actually damage your MacBook Pro by delivering too much power to it. But there are many cautionary tales to be found on the internet of third party chargers overheating, and occasionally catching fire or exploding. Technically, using a non-Apple charger without Apple's written permission may also void your warranty if anything did go wrong.

Personally, I wouldn't risk it.

Even an Apple charger can damage a Mac. It's far, far more rare since Apple tends to have superior QA and more motivation to make sure the adapter fails safely and fails before the computer would than the average knock off manufacturer is motivated by safety or adding cost for a margin of safety.

That being said, there are many good chargers that will work just fine. The main risk is fire from a poorly constructed transformer as opposed to down stream damage to your Mac since the magsafe port delivers between 3 V and 25 V DC it's not a huge amount of power or danger to life or hardware.