I'have alwayes kept my LTCs into a paper wallet.
In order to spend them, i have installed on a pc a desktop wallet (Electrum ltc) as i read in other forum.
I made these steps:
1 - File > New/Restore
2 - Choose the wallet name
3 - Mark "Import Litecoin address or private key"
4 - Entered a ltc prvkey and password

Maybe, heedlessly, i entered the public address instead of the prvkey, so i have a watch only wallet with my LTCs.
I have found no possibilities to get back to a spendble wallet or in the paper wallet again (at least).
Please, are there anyone can help me?