Hello,
is it possible, that there will be a bitcoin fork or swap in the future,
and all who forget to swap or follow the fork could lose their bitcoins?
Was there such a situation since bitcoin exists?
Or is it safe to store the bitcoins in the electrum wallet,
and we don`t have to care about anything?
Hard fork simply means change in the network consensus rules such that the nodes no longer accept transactions/blocks based on old rules and vice-versa. There is no notable and intentional hard fork in Bitcoin Network so far. However, there were few patches to eradicate network vulnerabilities from time to time.
But since you are just holding bitcoins on a non-custodial wallet, you needn't worry about anything. In fact, you are not storing bitcoins on Electrum wallet. Your coins are stored on blockchain associated with your private keys. If you have safely backed-up your seed phrase (or private key) then your coins are safe. Even if, Electrum doesn't upgrade to the new consensus rule in the event of any future chain split, you can simply import your seed in a compatible wallet and spend coins on a new chain.
Only problem may come if you are using custodial wallet. In that case, your wallet may not upgrade to the new rules and you will be unable to spend coins on new chain.
