LA--you are going to end up paying your lawyer a fortune to argue over things that aren't worth it (like the string of lights for example).
Do as Peace suggests and change the locks. He is living elsewhere. Then keep a list of the stuff he took and the value and hand it over to your lawyer when they make the big list of who gets what.
Remember that when you respond to this stuff you are just playing into his narrative of what a nut job you are and why he needs to divorce you. Just let it go.
It's easy for me to say that because I am further down the line and my H only took a few clothes and kitchen and garage items that I didn't even want.
In the beginning I made lots of excuses to contact him and they were all facially legitimate. I think at this point I'd rather cut off my arm than contact him for anything. It isn't fear, just distaste. I don't like giving him anything. I don't want him to think that I care about him in the slightest.
Whether he has served you or not you can likely get on with the show by filing an answer if you want to move it along (talk to your lawyer if you do). If not, do nothing, but stop contacting him and don't remind him that he hasn't served you.