Housings for a sensor consist of 2 main parts.
The most common form of housing for the main electronics is in the form of a small plastic experimenters box. They come in all shapes and sizes.
Its also possible to get them with compartments built in for batteries which makes them ideal for sensors. Being plastic its also easy to drill holes etc to mount switches in.
The receiving diodes need to be protected while mounted on the head. This requires an IR transmissive housing. In the past I have used 2 methods to protect them.
The first method I used was to encase them in clear resin. This makes them totally waterproof BUT has the downside of you cant access them later for repairs or whatever. I found an icecube tray that made dome shaped ice cubes. It made a perfect mold for the resin being perfectly smooth.
The second method was to use domes made of thin perspex/acrylic. This method works very well. The perspex domes are hot glued to perspex backs, providing a watertight seal that can with a little effort be opened if neccessary.
resin domes and main sensor housing
The actual domes can be attached to any suitable headgear with velcro (hook side on the domes, loops on the clothing). It makes it easy to change your headgear to something suitable for the games you are playing.