would a glass candle holder set deep into the center of a wood post be a fire hazard?

[addicted2crafts.livejournal.com]

I'm making candle holders out of 4x4 douglus fur posts, cut to size, and the craft originaly used tea light candles, but I'd like to use something a little bigger, and wondered if those glass votive candle holders would present a fire hazerd tucked inside the 4x4. The fire hazard wuld come from a bare flame being near wood, and with the glass to be between the flame and the wood I don't see how it'd be a hazard.