Tap into home ADT System sensors

Can I tap into my active ADT wired alarm system to take advantage of the existing motion and window/door sensors even arm or disarm via Hubitat?
I'm not opposed to purchasing a bridge of some sort

The konnected.io Interface should do what you want. I haven't seen anyone here using it or read any reviews, so I'm not sure how well people people like it in use. This is a relatively new product from them; their original "plain" panel product is widely liked (but that one replaces the existing alarm system, not supplements it). Take a look at their website and see, or maybe someone else knows of other options.

It depends on what you have exactly. Best bet is to take a peak at the panel and see what it is. Most seem to be the Honeywell Vista 20-P or some variation of that. I believe like @bertabcd1234 said the konnected device works with that. There are other way too. I have something similar and use nutech's ad2pi device to interface with the panel and hubitat. It works pretty well. Let us know more specifics and we can probably guide you better.

Depending on your alarm panel you can get an Envisalink and tap into it without having to rewire anything and without having to cancel your ADT contract if your still in one. There are apps and drivers for Honeywell and DSC in the code share section.