Hi Leinad,
I have fixed a few doorbells displaying intermittant ringing. The switch contacts are so close together they sometimes make. I've had car horns do the same.
Replace the switch if its easy and if its a nuisance.
As to the TV. It may have been switched off and bounced the finger on the switch which turned it back on.
If those are not plausable reasons then call Ghost Busters.
Cheers Marty