What would cause a afci breaker to trip by touching the neutral and equipment ground together this is on the last lite in bedroom circuit the rest of the circuit is fine Rang out hot wires and none are touching the grounds.
As far as I know, all AFI breakers (and GFI too) will trip if contact is made between the grounded and grounding conductor on the output side of the breaker.
GFI receptacles will trip too under the same circumstance.
Sometimes the AFI will remain latched with no load on the circuit and then trip when load is applied.
I've had personal experience with that one, a customer had run a drywall screw thru the NM cable and made contact with the ground and neutral conductors. Took a while to figure that one out.