Files can be transferred from one phone to another via Bluetooth, Xender,Flash Share, etc without any visible cord connecting both phones.

Is it possible to transmit electricity wirelessly like that from a power source to a phone or extension? If there is electricity in the next house but not in mine, is there any appliance I can use inside my house to charge my phones with my neighbour's electricity without going over to his/her house to give him/her my phones? Please mention the particular appliance, brand name and cost.

It is good if you get your own powerbank to charge your gadgets

Adeboyefa:
Files can be transferred from one phone to another via Bluetooth, Xender,Flash Share, etc without any visible cord connecting both phones.

Is it possible to transmit electricity wirelessly like that from a power source to a phone or extension? If there is electricity in the next house but not in mine, is there any appliance I can use inside my house to charge my phones with my neighbour's electricity without going over to his/her house to give him/her my phones? Please mention the particular appliance, brand name and cost.

Dear OP,
Such technology doesn't yet exist in 2020, maybe it will in the future, but I doubt.

File transmission and charging and 2 different protocols. Battery charging requires a Electrical power, which can't be done wirelessly. It's like asking if you can have electrical power in your house without connecting to the power grid. For now, it's IMPOSSIBLE.

When you hear phone brands say 'Wireless Charging' they mean charging the phone ontop a phone charging pad.

Adeboyefa:
Files can be transferred from one phone to another via Bluetooth, Xender,Flash Share, etc without any visible cord connecting both phones.

Is it possible to transmit electricity wirelessly like that from a power source to a phone or extension? If there is electricity in the next house but not in mine, is there any appliance I can use inside my house to charge my phones with my neighbour's electricity without going over to his/her house to give him/her my phones? Please mention the particular appliance, brand name and cost.

Yes it is possible depending on the distance. It works only 40ft length or less. It is DIY wireless charger. I have done one before and it was working until it got missing. Make use of search engines.