The ON/OFF button does not work

Dear sir or madam,

The ON/OFF button on my daughter's kidizoom camera did not function after a while. All other buttons in line were OK. I opened the camera, dismantled it almost completely and found the tip of the button which comes into contact with the circuitry was molten and therefore shorter than it needed to be.

Is there a spare button or another button of the same size I can purchase to install in the camera and have it operational again?

Thankyou in advance.