Oil painting on black velvet of venice in lights 4.5 ft by 2.5 tall

This was given to a Mother about 70 to 75 years ago, from her son who was in the service, bought in Italy, when removing the back, there's a string of lights, that lights up all the windows in the painting, it's signed but can't seem to find anything on the artist any information would be appreciated, and would like to know what it worth is