I have had an interesting situation with my camera charger. The charger was plugged into an outlet in the bedroom and when I turned on the ceiling fan today, it was turning much slower than usual. I brought a desk fan into the room and it was turning slower too and on top of that, there was some sparking in one of the power outlets. The moment I removed the camera charger from the outlet, the fans (both) started working fine. The sparking stopped.

What was happening here? I'm an electrical engineer by education so can understand technical explanations.

Thanks,
P.

Remove the outlet and see if it was wired using the little quick connect holes in the back. These are notorious for developing poor connection after a period. If you find that the outlet was wired by "back stabbing", (technical term) remove wires and put under screws. Then do all of the rest of your outlets and switches. If you don't find "back stabing" look for other reasons for loose connections. Back stabbing doesn't usually cause sparking. If metal boxes were used make sure that all unused terminal screws are screwed in. Extended out they can some times make contact with the box if it is a small box.

May have been Intermittent, not a short, a short may have tripped the breaker. Making solid connections in sparking box will fix.

The problem is that sparking occurred in the outlet immediately outside the room in which the chargers and fan were in. I'm wondering if the charger was causing a short or at least a high current draw? Also, I think the fuses are a little out of spec for this portion of my house.

Its just loose connections, tightening should fix.

Thanks. How do we explain the fans?

Loose connections mean more resistance, means slower speed. Loose connection is probably in neutral wire.

Your reply makes sense but I'm trying to understand why the loose connection happens when I plug in the charger into an outlet that is different from the ones giving out the sparks.

The load of the charger is passing through the loose connection at the other outlet.

If you have other lights that go bright when this happens, it could be a multicircuit(2 hots on opposite phases sharing the same neutral.
Then it would likely be a neutral.
I think it could be the Hot or the Neutral.

Your charger has probable got a short circuit
Or maybe their power junction box to split the power is unbalanced

Have you tried it in other outlets?