Emergency! Please help, please!

[Campos21]

Alright, well my phone was acting great and everything yesterday, then i was at the amusment park and my phone died...i didnt get home till midnight, and i put the phone to charge right when i got home, then my phone turned on by itself, and i didnt turn it on...and i let it sit there for like ten mins, and when i took it off the charger, i took the battery out...then i put the battery back in and the phone turned on again and i didnt press the power button..then the phone turns on, and all it does is vibrates, and locks and unlocks?
any reason why?
thats all its been doing...the screen will turn black, then normal again for like half a second, and then start to vibrate and do that over and over again..and it vibrates everytime i press the screen to, and slide open the keyboard...please help, please!