Yes! You can certainly do a weight training workout at home using old school methods using all safety measure to avoid injury. These exercises can be done using things around the house creating weight dumb bells, these can work great for maintenance increase mass, strength, and condition.Also adding your cardio workouts will help .
Get a few things you can use anytime even when you have started back in the gym to help with maintenance. You will also be able workout with these things while you are travelling away for work or vacation. These are Medicine ball, Bosu /Stability Ball, Resistance Bands, and Chin up Bar.
Chest(Pecs)/Back(Lats)/Shoulders(Delts)/Arms(Bi/Tri): Chin ups/Pull ups
varying grips and width of grips you can target several muscle groups doing various exercises.
Push Ups – Incline, Decline, Single, Wide, Narrow and Military hands
Legs(Hams/Glutes/Quads): Squats, Lunges, Step ups, Single Leg Dead lifts , Jump Squats
You can do Resistance, Body weight and interval training using either type of training if you choose or do use a variation of sets and reps; either by super setting, descending or pyramid sets.