Short Circuit Question
Your electronic appliances are safe.

House wiring is parallel connection like this:



Image source: Electrical Technology - How To Wire Lights in Parallel?

This diagram shows three bulbs but you can imagine your router, AC, TV etc connected in a similar fashion. 

Right at the supply end, there will be an MCB to break the circuit if any of downstream appliances gets shorted. 

When a short circuit happens (assume bulb 3 which is OFF in the diagram above), the shorted appliances will draw a huge current from the source. It has to be noted that the current will not flow through other appliances because of the way they are wired. If it was a series connection, current would have had flown through all of them but for a household wiring (Parallel connection), the current won't go through all of them.

When MCB's threshold is reached, it opens the circuit. Worst thing that could happen is wire damage in case your MCB cut off rating is higher than what the wires can safely handle. In some cases, it can lead to fires as well.