Electrical

I have a 1999 F150 with the 5.4 triton v8 and 90000 miles.A few days ago it refused to start when I turned on the ignition switch. After a few tries it finally started and ran fine but when I shut it off the heater fan kept running even with the key out of the ignition. This time when I tried to start the truck it fired right up but the wipers and radio didn, t work at first. After a few minutes running they both worked fine but when I shut the truck off the radio stayed on. This time the fan shut off. The next evening when I went to get in the truck the lights were flashing sporatically and the starter was trying to engage.I started the truck but the srarter was still trying to engage so I unhooked the solonoid wire from the ignition switch and this stopped the starter from engageing but the interior lights started flashing and the 4x4 light on the dash started flashing on and off and I could also hear a relay clicking under the Dash.I talked to a local mechanic and and he thought I had a remote starter that was back feeding power to the truck. The only problem with that theory is I don't have a remote start. Any help would be appreciated, thank you