My phone keeps on flashing as if it wants to freeze

[T911]

Help me to make this settled. 

[-Robot-]

Could you provide more info? It is hard to try and help you without it

[AndrewL]

@T911: Are you using a particular app or feature when this issue occurs, and does the phone become unresponsive to touch interactions at any point? Has the device been subjected to any physical or liquid damage and, if so, is there any damage to the screen itself?