three beeps pause

I have been hearing some kind of alarm over the last few weeks that doesn't sound like a car alarm, nor a house alarm but more like an alarm clock alarm....only REALLY LOUD!

It goes of randomly during the night and day (I notice more at night as there is less white noise to drown it out) and is intermittent.

It can go on for a couple of hours at a time and occasionally stops, and just when you think it's over it starts up again beep beep beep pause beep beep beep pause beep beep beep pause!

It has managed to wake us up in the middle of the night and also been going as we get into bed and therefore it's hard to get to sleep.  

This morning it started at 4.45 beep beep beep pause beep beep beep pause beep beep beep pause!

This time it was annoying enough that it got me out of bed and had me wandering the streets to find out what it was and where it was coming from looking like a crazy lady in my pj bottoms and a coat 

I ended up tracing it to a garden/house in Frobisher Road but no further.  It was too early for me to knock at the house so may do later.

Can anyone else hear this and does anyone know what it is and can someone PLEASE MAKE IT STOP

Anyway, I will not rest (literally) until I find out what it is and sort the situation out.