JR, yes, they are incandescent. Most likely, they are 3.3-volt bulbs in series, about 40 of them (40 x 3.3 =132). If they dim, then they will work with the dimmer module.
If there is a receptacle on the far end of the string, then the string is a 3-wire assembly; the third wire carries the current to the far end of the string for the receptacle.
Larry
www.fineelectricco.com