PC automatically wakes up when I turn off the light in my room

SubFPS

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Feb 4, 2014
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That's right. After I click the Sleep button while the fluorescent light tube in my room is on, it goes in to sleep mode properly and everything in the PC turns off. After I turn the light off in my room, the PC automatically wakes up.

Sometimes the PC also automatically starts up in a couple of seconds after it shuts down safely and completely.

My PC is connected to an UPS. Specs in signature and in thread hyper-linked below.

What is causing this? Also can this problem be related to my still unsolved issue on this PC?
 

SubFPS

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Feb 4, 2014
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@PsychoGamingLemon: No, the light is connected straight to the wall without a plug.

@tea urchin: Yep, the UPS is new. The UPS however is connected to a power strip which is connected to the wall socket. The power strip is a really cheap one (like $3 if converted from my local currency) so not sure if it's anti-surge.
Can you please tell if it's related to the other two problems I underlined in the OP?

I just noticed that it's happening with anything I turn on or off in my whole house, not just the fluorescent tube in my room. I also tried using a voltage stabilizer, same thing happened.