Then your computer is infected with malware.
Did you verify the transaction
after pasting the address ?
Clipping malware is quite common. They check your clipping board for BTC addresses and replace them with the attackers one.
Try copying the following address and paste it somewhere (e.g. notepad):
136jLgnKfTsp94XdPdZqeHzspAqdPc5pLW
If the pasted address is not the same you have copied, you are a victim of such clipping malware.
If the pasted address is the same as the one you have copied, your machine is infected with a different kind of malware.
In this case, check your electrum version. Are you using the installed or standalone version ? Verify the signature (e.g. standalone executable or installer).