Great advise jatrax!
One other thing to add to his list is easy to check yourself. Examine your wires to the troubled cylinder. A rodent might have chewed the insulation off the injector wire or coil wire causing an occasional arc to ground, hence causing the occasional misfire. If you find any insulation chewed off, wrap the exposed wire with electrical tape until a shop can make a permanent repair with shrink tubing, or if bad enough, splice in a new connector with pig tails.
A strong indicator of rodent damage at a glance is if you see a collection of natural material made into a nest sitting on top of your engine. Those cute little critters move in and eat at the restaurant closest to home.
Rodent damage is common on vehicles sitting outside for extended periods, especially sitting over the winter when food is scarce. Motor homes are most susceptible. Mice will make a meal out of wire insulation, vacuum tubing, and spark plug wires. I see rodent damage often on vehicles donated to the non-profit where I am a volunteer mechanic. Donated vehicles have often sat around outside a while before the owner decides to donate it.