Luhr-Jensen Little Chief electric

Look under the smoker at the wiring....  sounds like a bad connection causing high amperage..... UNPLUG the smoker first.... 

A hot plate will not work well in the smoker....  rebuilding what you have would probably be the best choice... 

What is the AWG of the extension cord....  should be 14 or 12 AWG .....   If you home is an older home, the circuit breaker could be worn out..  even new breakers can be bad....    Where the ext. cord plugs in, grab the cord and feel if it is warm....  The male legs on the cord end could need "spreading" apart....   put the blade of a box cutter into the spade slit and gently open the slit so the spade lugs spread and make better connection in the outlet...  

                                                           
Dave