Detectives are looking for two men who threatened and robbed a carer as he looked after a disabled person inside the home in Armadale on Saturday night.
Police said the suspects attempted to open doors and look around the home.
But as they went to enter the bedroom, the male carer in his 30s placed himself between the men and the bedroom, police said.
The men stole the carer's mobile phone so he couldn't call police and then fled.
Police described the men as fair-skinned and both had medium-large builds.
The two suspects had short dark hair, police said, with one having facial hair and the other sporting a "French-style" moustache.
Police believe the men are locals.
Detectives are investigating whether comments on a local social media group that incorrectly identified the residence as being for former prisoners may be linked to the incident.
Investigations are continuing.