Being an ed tech at a public school does not mean you are just a babysitter. You are not just there to make sure the child does not hurt themselves or hurt others. Sometimes that isn't even an area of concern at all for the child. You are there to help them interact with the academic and social world by finding creative avenues to get him involved. In music class you might find out he can memorize a song one time after hearing it if you just made eye contact with him and made sure he saw your lips when you were singing. He may be able to do simple addition but in a different format than the rest of the class. Don't just walk around with him holding his hand when he can actually walk down the hall by himself. If you want to hold his hand engage him while you are walking with him. Don't talk about him like he's not even there. He may not contribute to the conversation but I bet he understands close to everything you are saying. I don't want to lump all ed techs into this category, because I have met some wonderful ones, but I have seen my share of cruddy ones too. If you are looking for an easy job that doesn't take a lot of initiative, creativity, and motivation then you should apply elsewhere.
Putting soap box away now.