The people have gone on holiday so I haven't talked to them myself. However, I did complain to the Management Company. I've seen a few alarms with blue lights but this is like a strobe. Anyway the MC sent a guy around today to examine it and he took it off the wall!! He said it was a false box with a battery operated flashing light which probably shouldn't have even lasted a week. He thinks they put it up BECAUSE they were going on holiday and wanted to give the impression the apartment was alarmed.
It's amazing really, they were willing to fall out with the neighbours over something that probably could have been turned down. If they'd explained what they were doing to our tenant, she's the type who probably would have said ok, as long as you take it down when you come back. They decided to take a hard nosed and rude attitude which upset her and so she called me. Actually the light might have affected her epilepsy as it can't possible be regulated in any way.