Did you see the Wall Street Journal article today?  Huge investigation of multifamily mortgage fraud.  One thing they did was fake occupancy by having radios playing in vacant units!  Several complexes are facing foreclosure.  This could get interesting...

https://www.wsj.com/articles/u-s-pursues-one-of-the-biggest-mortgage-fraud-probes-since-the-financial-crisis-1534357872?mod=searchresults&page=1&pos=2