Sleep Tight (2011) - Synopsis

Concierge Cesar (Luis Tosar) believes he was born without the ability to be happy and endeavours to make life hell for everyone around him. The majority of the tenants he encounters are easy to agitate, but new resident Clara (Marta Etura) proves harder than most to bring down. A terrifying obsession is born as Cesar goes to creepy extremes to destroy Clara, who in turn starts to question how safe anyone actually is in their own home...