Had this happen before, who'da thunk it'd be you and me sharing this stupid experience eh Bro??
Our phone, years ago, was a fairly standard model, nice cheap circuit-boards and all. One day it got some crap spilled on it (I think it was beer) and we quickly toweled it off and aired it out.
I guess it wasn't fully dry right then and there, but it worked fine, no shorts
A few days later it started producing wrong numbers pretty much every time and finally it got so bad that dialing 227, 684, any local prefix connected us right to 911. After 3 times of this happening they basically said it had better not happen again. We replaced the phone and never had the problem again.
I suggest a possible short in yer phone from whatever, could be long-term deterioration, could be humidity, could be anything, but I have heard from a few other buddies similar tales, somehow I think it goes kinda "binary" when it fails and the only tones it'll make are 9 and 1
On a related note I have called 911 thrice, once while riding my bike I saw I guy foolishly trying to cross a busy 4 lane highway- he didn't make it and the driver was freaking out on the other side of the fence (this was before cellphones) so I rode to the closest payphone and summoned the authorities, one time when I saw a guy wipe out into a curb on his bike (seemingly TOTALLY drunk) and just lie there motionless, and once when the OLOD lady across the street slipped on some ice while retrieving her recycling bin, she was shredded up pretty good, and the operator asked where the problem was, then stated that I was NOT calling from that address and gave me a hard time about that fact while the lady lay in the snow bleeding profusely- why would ANYONE call in that kind of practical joke at noon on a weekday??