It will be the ones circled in yellow and bolted to the circled in red nut.

First just wanted to know if there is indeed supposed to be two wires bolted to that nut. And second if one wire is supposed to be a hot wire, and another supposed to be 0v. The hot 12v wire bolted to the shell of the ecu makes the whole shell of the ecu hot, I tested with my multimeter and recieve 12v reading on the shell. Is this normal? And since the ecu is bolted to the ground well just sounds like thats not right. Also, the shell of the ecu will produce sparks as well when in contact with ground.

 

The two wires should be ground ,Check the with an ohm meter . Allways disconnect the battery ground when taking the ecu out . If you have the battery hooked and you unbolt the two wires and move them fron the ecu then unbolt the ecu from the mount and move it away then you will get a spark .This is not good .Undo the neg battery cable and ground the ecu before reconnecting the battery for the ecu safty .Better safe than sorry .