Your 2002 ford F-150 has the service engine light on and you got it tested and it detected a misfire in clyinder 1 what could the problem be?

The coil for that cylinder is probably bad. replace it.

If you have a coil pack, they run around 60 dollars and are easy to replace. I recommend replacing the sparkplug wires also when replacing the coil pack I have had a bad coil pack fry my wires. Go with motorcraft spark plugs also. The engine was designed for them and some of the other plugs run too hot