Thanks for all the welcomes.
Ok I will post problem here. Me and girl are renting a room, but it's actually a detached 2 car garage. We have fridge, microwave, propane stove but we go in house for bathroom needs. There is only one outlet by the door so the terms "extension cord" and "power strip" are heard often around here. Space heater or AC is impossible because it will trip the breaker, but I already guessed that when I saw lights dim when fridge compressor comes on.
In the last 2 weeks, sometimes plugging or unplugging anything will cause something else to go off, and its always something video related, such as turning on a fan caused PC monitor to go off, or plugging in a lamp will cause TV to go off, and that's on other side of room using a different power strip and extension cord.
And the night before I made this topic, the microwave caused the breaker to trip, and that has never happened in the 6 months we have been here. I checked all cords to make sure they are securely plugged in. Any ideas?