Camshaft Position Sensor broke off?

I've had these break before. If there is enough of the sensor to bite onto with vise grip pliers you might be able to wiggle it out this way. If not, try drilling a hole in the plastic to put a screw into and pulling the screw out with a vise grip pliers on a slide hammer.
If all else fails, you might have to remove the engine oil pan to get to inside side of the sensor to push it out from the inside.
There is usually rust that builds up around the hole making it very difficult to remove.

The one thing you don't want to do is damage the tone ring inside the engine that this sensor is reading.

Hope this helps and let us know the outcome.