Brake problems

So I had a prius V at my shop which had a bad brake light switch, I did not have the part on hand so I took the part from my 2012 prius. The part did not match up so I took my brake light switch and reinstalled it. Ever since then my cars brake pedal will become very hard and will shoot back up while stopping the car by itself. This will only happen going below 15mph. The pedal in general is stiffer and whenever I press the pedal I hear a fluid clicking noise in the pedal. Is this a bad brake actuator? Or is the brake switch bad.