A motorized lock actuator adapted to replace a mechanical lock actuator in preexisting and installed lock assemblies to convert them to electronic operation includes an electrically insulated motor housing and at least one electrically insulated bushing on the motor shaft to prevent electrostatic discharge and EMI/RFI interference from damaging the electronic lock controller. An alignment spring is used to improve operation in misaligned lock assemblies, and a key cam of self lubricating and electrically insulating plastic provides reliable low friction operation for a sliding locking slide assembly.