can you please tell me how to fix my iphone 6?

[iMore Question]

it keeps switching off and on?

 

[SwitchBeach]

More details are needed.
Has the device experienced any physical damage? Dropped? Sat on? Run over by car? Gotten wet?
Have you tried a hard reboot of the device?
How much free space do you have on the device?
When did this start happening?
What happened to the device right before this started?