Wont turn off, blinker honks horn

Hey all
I have a 1997 2.4L taco
Yesterday when I went to move the truck the horn honks while I signal.
I thought odd, looked at a couple things on the internet and figured it might be a short or maybe ill just disconnect the horn... problem solved.
Today, when I went to do that I opened the door and the engine oil light was on, but the keys were not in the ignition. I started it up, all lihgts went off and I drove down the block closer to my house.
There I noticed a leak on the exhaust manifold on the left side of the engine. A bit of smoke form it burning off the hot pipes, so I shut it off and removed the keys.
This time the oil light was still on and I noticed I can turn on the heat with out the keys being in.
What is going on with my truck? Any ideas?

 

Check for rodent chewed wiring.

 

Maybe it was damaged in a flood and now all of a sudden weird shorts are appearing

 

Sounds like you have water entering or corrosion somewhere in your electrical system.

check your floor under the dash for wetness or rust streaks.

 

Interesting suggestions so far.
Ive owned the truck for almost 15 years and it was my uncles before that, no floods.
Think its bad to drive around in? I mean, if it starts up with no warning lights on and drives, could i be making it worse?

 

Is there an aftermarket trailer wiring installed?

 

This

 

No aftermarket trailer wiring.
Im looking for the chews, under the hood and from the floor up.
Tomorrow the dash may some off.

I did hear some crackling, like two small wires constantly touching each other, but saw no sparks.
Thought it could have been outside noise, so I unplugged the battery and the noise stopped.

If I unplug the battery, there us no way the air bag can deploy when taking off the steering wheel, right?

 

Taking off the steering wheel would only happen after you've eliminated other things. For sure disconnect the battery if you're going to do anything with the airbags.

 

Any left over parts of an alarm?

Your horn and flashers are not switched power.

Your issue might be poor grounding causing the interesting electrical issues.

No need pulling everything apart to figure out the issue

 

No old alarms.
Grounding is something to look at.

 

Check harness under the seat. I had a bad electrical nightmare myself and it was a wire under there. Good luck!

 

update
pulled the fuse under the hood for the horn
blinkers still work but does not beep the horn when i try to turn
i do not hear the buzzing anymore wither.
I did notice some moisture when i took off the panel under the steering wheel.
Maybe thats to blame?
regardless, im driving around fine and cant make anyone mad anymore by beeping at them
win win?