Getting 240v is surprisingly easy in North American homes because a 240v connection (like a stove and dryer) is just the product of two out of phase 120v connections.
How do you find which plugs are out of phase?
For wiring two connections together, this video describes the process fairly well:
Some plugs, such as those in modern kitchens might even have two phases in one location such as seen in this video:
Be cautious when using this approach and ensure both plugs are connected and disconnected when using/not using the 240v connector. Otherwise you will make the male prongs of one 120v live if you only plug in one connector and then turn the machine on; causing a shock hazard.
Overall, doing this is a hazard and not recommended; but that doesn’t mean it won’t work in a pinch.