Hi
You are right, my apologies for the mistake. I associated it with the commune because of its wikidata and wikipedia tags.
San Miguel is indeed a place of Pedro Aguirre Cerda. It is the name of the "Unidad Vecinal" (neighborhood unit) 11-A, as defined by the municipality of Pedro Aguirre Cerda.
Interactive map in the official page: http://www.pedroaguirrecerda.cl/Secplan/limites.html