Soak wood chips in water at least 30 minutes.
Prepare charcoal fire in smoker; let burn 15 to 20 minutes.
Stir together butter and thyme.
Remove heavy outer husks from corn; pull back inner husks. Remove and discard silks. Rub corn with butter mixture. Pull husks back over corn.
Drain chips, and place on coals. Place water pan in smoker; add water to depth of fill line. Place corn on upper food rack; cover with smoker lid.
Cook 30 to 40 minutes. Remove from smoker, and let stand 10 minutes. Pull husks back, and serve.