'This Is It' Director Kenny Ortega -- Cops Respond to L.A. Home

LAPD officers raced to the home of "This Is It" director Kenny Ortega last week ... after an alarm went off in his home ... and TMZ has learned cops called in a chopper to help search for a possible bad guy.

Law enforcement sources tell TMZ ... there was a breach in the garage that triggered the alarm ... and the alarm company notified police.

We're told when cops arrived, they didn't see any signs of a crime -- but just to be safe, they called for the eye in the sky to search for a possible crook ... who may have been scared off when the alarm was triggered.