Marine supply stores offer low wattage heater sticks expressly for dehumidification. They're not expensive and far safer than a room heater or light bulb. I'd also consider making the closet more theft-resitant with a heavy duty door, hinges, and lock. At a minimum, line the inside of the door with 3/4" plywood and install a deadbolt. It won't stop a determined thief, but it will slow and hopefully discourage them. Look
Will audio gear be ok in unheated house
I have a cottage. I drain the pipes and the house is left unheated over the winter. I have been taking my audio gear home (except for the speakers) when I leave in the fall for theft worries, but mostly because I am not sure the equipment will be OK in an unheated house in an often damp environment until the late spring when I return.
It is a pain taking it back and forth and I would prefer to leave it there. Maybe in garbage bags with some bags of dessicant in the garbage bags.
Anybody have any experience with this. I have been unable to find a good answer searching the web.
Thanks