Emergency operators got the call just before 9 p.m. Wednesday. The caller reported a kidnapping and shooting at the Studio City home.
Within 30 minutes, police realized it was all a hoax, and no one, including Cyrus, was there.
It's a stunt that officers say could prove dangerous.
"The danger is that we have multiple units responding 'code 3' to what we believe is a crime in progress. Then to find out it was a prank puts a lot of lives at danger," said LAPD spokesman Karen Rayner.
A 911 call that turns out to be a hoax is a misdemeanor, but it becomes a felony if someone is hurt as a result.
