Dome lights will not turn off, fuse sparked when I removed one

The fuse would arc because of the lights being on and drawing power. The issue could be a bad switch that controls the dome lamps, a possible test would be to use the dome light bypass switch. If the bypass turns off the interior lights, then the issue is likely a switch as the bypass opens the circuit. Failed door switches are common as is the circuit wires grounding out as that is what the switches do. If the bypass works, the next step would be to remove the switches one at a time and disconnect them. The one that turns the lights off is the one that's stuck on.

Thanks for the response. Does bypass mean dome override? I tried that button several times and it didn't turn off the lights. Should I still check out the switches or would it most likely be something else?

If the fuse is out can the lights still somehow draw power? Or is it only when I reinsert the fuse that the metal prongs cause the arc? I'm wondering if I should unhook my battery if there's still a draw/short.

If the dome override doesn't turn them off then it isn't a switch, Which lights are on? All of the dome lights or just one or two lights? The way they work the orange wire carries power to the interior lights from that fuse, then the lights are grounded on the other side to turn them on. Do you have remote keyless entry? That has a timer that turns the interior lights on when activated and it's possible it has a problem. Or it could be the dome light control module. However, if it's not all of the lights turning on it's possible it's a short only for that light.
With the fuse out the lights should go out; they only get power from that fuse. There isn't any draw with it out.

It's only the rear and the center overhead that are stuck on. The front overhead and all of the reading lights turn on and off as normal. I don't have remote keyless entry. I'm thinking about popping off the ceiling panel and checking to see if I can spot the problem. It would be an orange wire? Is there anything visually that would tell me where the short is?

Okay, that changes things a bit. If it's only those lights that are stuck on it's likely a localized problem with the white wire that grounds to turn them on/off. Is this van equipped with the courtesy lights in each door? Does it have a roof console? How about the map lights in the center lamp location? These vans were built using multiple layouts, but many still have the wiring for the other versions tucked away. Those two lights are fed power through the orange wires and are turned on and off with the white wire. Except for the center lamp which has map lights, it has a switch that turns the map lights on and off that could ground the other lights if there was a problem inside the lights.

Courtesy lights, yes.

Roof console, no.

Map lights-I'm not sure if the "reading lights" are called map lights but they have their own button to turn them on and off

Pic 1-above dash. Nothing electrical.
Pic 2-first overhead light right behind front seats
Pic 3-center overhead light (cover off)
Pic 4-5-door lights
Pic 6-rear light (cover off and bulb out)

I'm not an electrician, but it's sounding like the problem is somewhere in here:

Yeah, the reading lights are map lights. They got that name way back when paper maps were common, and the navigator read the map but wanted to keep the light away from the driver.
Do the map lights turn on and off like they should? So far it sounds like an issue with the white wire that grounds the lights. One item that might help would be to unplug the interior light control module, it is mounted up next to the OBD port under the dash. It controls most of the interior lights and unplugging it might isolate the fault. If unplugging it turns the lights off then it is faulty, if it makes no change the issue is the white wire, probably a grounded splice point behind the headliner.

Where you outlined could be the area, but all of the lights ground through the same splice so if both of those lights are on, the others should be as well. That is why it's difficult, they have multiple lights connected to the same points.

Sorry, I had to finish up another project. All the map lights do turn on and off as normal. I found the control module, but could not get it unplugged. I lifted the clip but I think there may be another pin inside holding it shut. I gave up on that one for now.

When I put the fuse back in, I noticed that the stepwell lights were on as well, even with the door closed. The courtesy lights were off. So the only lights beyond that splice point that are working normally are the front dome and all the reading lights. Everything else is stuck on.

Do you have an idea of where I might find that splice point? If I pop off the roof panel would it be visible?

Okay, try again on that module, it's possible that it got hot and melted together. That could be what is holding it in and possibly the failure item as well. Attached is a cleaned-up version that removed the options yours doesn't seem to have. The lights you have stuck on are all connected through both the orange power feed and the white control wire. I would start with the simpler stuff first rather than going after the splice. Unplug that module, if the lights are still on then, disconnect the dome light switch in the dash. I'm thinking it is one of those that failed and is sticking the lights on.