PC wakes itself up in the mornings xD

Recently, like a month now, my PC has been waking itself up from sleep, like every morning I wake up its turned on, and everyone in my family is asleep.
This morning, I was watching TV and the PC woke itself up!
Why does this happen, also this only happens when I put it into sleep mode.
Answer #1
It could be because of a failed component that uses to much power and because of that waking up the pc.
Answer #2
It could be because of a failed component that uses to much power and because of that waking up the pc.
I agree with him, my pc actually does the same thing. Even if it is off it swtiches up in the morning. Might be cause by a variation of electricity..