99 ford tries to start on its own while running

PLEASE HELP ELECTRICAL GREMLINS so starter stays engaged after it running and sometimes tries to start, been throwing parts at it, tried ignition, ignition module, starter relay, starter, new power wire to starter, new switch wire to starter<had dash out to examine, no burnt or crusty wires that i can find. at my wit’s end, out of idea.s if you have any suggestions, feel free, please. oh ya, sorry, '99 ford f 250 2wheel drive 4.6 liter.

If there is a remote starter system installed on the vehicle I would suspect that is causing the issue.

Get it started and then pull fuse 21. That fuse is in line between the ignition switch and starter relay. If it then still tries to start, it likely is the starter solenoid (since you’ve already replaced the starter relay, that can’t be it).
If it then stops starting, it may very well be the ignition switch.

Does it have a starter solenoid on the right (passenger) side inner fender??

When you say you changed the ignition, do you mean the ignition switch. I have seen 90s Fords where the actual switch on the left side of the steering column was faulty (opposite the key). On close examination of the switch, the plastic pin that held the starter contact apart had melted leaving the contacts continually closed.