Alcoholic spouse

In order to prove my spouse is a alcoholic, how do I prove that for court?

Get as much evidence you can for as long of a period of time as possible to show a pattern/habit. For instance, evidence of his/her expenditures and keeping track of his/her consumption as best as you can.

Would a witness or witnesses be a good source to prove the habitual drinking/intoxication?

It depends on what the witness has to offer and the amount of time you have to present your evidence.

I dont know anything about how much time I’d have but my neighbor has seen his bad behavior from being intoxicated many times. She told me she stopped coming here to my house as much because she got tired of watching him be mean to me.
My two now adult sons have seen it too. One son is mine from a previous marriage and the youngest is ours together.

The reason for my comment is because you are asking me about trial strategy when I don’t know the entire facts of your case. I would need to look at the whole picture to determine what evidence is the most relevant for the judge to hear and how it should be presented. The bottom line: whether you put on witnesses should be decided based on the relevance of proving he is an alcoholic, your time constraints, and whether you can sufficiently prove the fact without the use of additional witnesses.