My son scripts as well. You might want to try a "script" for having a conversation. For example, you start by having your son answer a question.
What's your favorite color?
(1 word answer-blue)
Then, build into more than one word answer.
(My favorite color is blue)
Next, add more detail.
(My favorite color is blue because I like the Giants)
After that, teach to give ask a question to other person.
(My favorite color is blue, like the Giants. What color do you like?)
And so on and so on.
Kids on the spectrum need to have everything taught in a very direct, step by step way, including social skills:)

My son who is 8 years old now was a pretty heavy scripter when he was a little and did the same types of things you describe your son as doing. Sometimes he would be in context and other times completely out of context. Frequently, he would modify scripts (changing a word here or there) to communicate his thoughts or needs. Instead of having a "real" conversation with me he would want to be Spongebob and me to be Squidward. He would script lines from the show and then tell me what I was supposed to say for my character. I always just played along with it and, for him, it has gradually decreased over time.

However, it has never completely gone away and it is very obvious that he struggles to express his more complex thoughts and feelings. For example, I asked him why he likes Eggo waffles yesterday and he answered, "because they bring the whole family to the table". Umm... yea, that's straight from the TV :(

He sees a Speech Pathologist and she is working with him on his expressive language. At home, she has advised me to make a point of asking him questions that give him an opportunity to practice his expressive language and then probe for more information when I get scripted answers. Like the waffle example above, I acknowledged his TV answer with an affirming nod and then asked him if there were any more reasons why he liked Eggo waffles. Then, he told me likes them because they are sweet. I tried to reply more enthusiastically to that answer, "Oh, that's interesting!" and then let him off the hook to eat breakfast.

I wish I could give you more info. All I really know is to keep encouraging the quality communication and I definitely recommend you work with a SP if it's in your means.

In certain situations, I have been asking my son to keep the scripting in his thoughts. He'll keep it quiet for awhile and then forget and start talking again. He's learning.

I also suspect that my son scripts to entertain himself. I realize there is probably some clinical explanation that I just don't get but half of the time he is laughing out loud as he does it.

It was kinda funny today too because he and I went out to run erannds after I posted here about scripting. We drove past a Domino's pizza and from the back seat I hear, "Domino's pizza. Do you know that most pizza starts out as frozen dough but not at Domino's!" Umm.. yea, that's straight from the TV too. Commercials may be his new thing!

Yes. My son does watch movies & netflix shows over and over. Now he watches old VHS movies and rewind them over and over and over again. He become easly opsessed with anything then become fustrated at the object of his obsession. Hes mostly non-verbal so when he does copy tv or radio i am just super excited that hes talking.

Scripting is when they memorize and repeat strings of language, basically. So my fella watches TV shows over and over again. Eventually, he begins reciting the lines either to himself or in context. Sometimes it's clear he's calming himself. I noticed a while ago that if he didn't script at the store, he'd have a meltdown. If he scripted, we were great. He still does this, but now I notice that the script changes. Sometimes I'm swapped into the story, sometimes characters from other shows. Sometimes he'll even change up a script to incorporate a task he's doing. The framework is still there (these days it is about small head Jimmy ?!?) but if he's pouring a drink, he talks about Jimmy doing that instead of whatever he normally does on the show. It's pretty interesting.

Dezimom, is this what you are thinking of?