Rrring!

I get very nervous when the phone rings in the middle of the night.  Is it a wrong number or a bearer of bad news?  Most of the time I let it continue ringing until it stops and if no one calls back the next morning, I know it was a wrong number.  I wish someone would invent something to show whether it's good news or bad news or just a wrong number whenever the phone rings - perhaps a green light (for good news), a red light (for bad news) and an amber light (for a wrong number).  Then all we need to do is take a look and we don't have to answer the call if we don't want to!