Consider all wires, machines and appliances inside a structure potentially energized, and stay away, even if you believe the power is off. There may be other sources of electricity in use, such as backup generators or solar batteries.
Do not pull a meter or disconnect a service wire on a potentially energized structure. This is extremely dangerous and could get you shocked. Turn off power using the main switch only if you are trained to do this and the utility has confirmed that it is safe.
Keep your palms turned inward when entering any structure. If you contact an energized wire, muscle spasms may cause your arms to contract; with palms facing inward, your arms and hands will pull away from the source of electricity. (Be aware that turning your palms inward will not protect you in the event of a high-voltage shock.)